Signed-off-by: NHongtao Gao <hanahmily@gmail.com>

* [maven-release-plugin] prepare release v8.1.0

* [maven-release-plugin] prepare for next development iteration

* [maven-release-plugin] prepare release v8.0.0

* [maven-release-plugin] prepare for next development iteration

* Remove all shardingsphere cases.

* Group Parameterized Endpoints. Configure the grouping rules for parameterized endpoints, to improve the meaning of the metrics.

Here are the basic and simple usages of the MeterSystem APIs.

## Meter Creation
New meter could be created based on metrics name, function, scope and data type. 
1. Metrics name is still the storage entity name.
2. Functions are every similar with the OAL function, just accepting different input.
```java
final MeterSystem meterSystem = MeterSystem.meterSystem(getManager());
meterSystem.create("test_long_metrics", "avg", ScopeType.SERVICE, Long.class);
```
NOTICE, this creation should only be called in the `module#prepare` stage, otherwise, `Can't create new metrics anymore` exception will be raised after the **CORE** module `start` stage finished. You may find out, there is a chance `create` could be executed successfully in your own `module#start` stage, but it it just because of the sequence of provider loaded by the class loader, **no guarantee, so please don't do that**.

## Runtime Calculation
`AcceptableValue` is the object created at the runtime to accept new metrics value.
```java
         final MeterSystem service = getManager().find(CoreModule.NAME).provider().getService(MeterSystem.class);
        Executors.newSingleThreadScheduledExecutor().scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                final AcceptableValue<Long> value = service.buildMetrics("test_long_metrics", Long.class);
                value.accept(MeterEntity.newService("abc"), 5L);
                value.setTimeBucket(TimeBucket.getMinuteTimeBucket(System.currentTimeMillis()));
                service.doStreamingCalculation(value);
            }
        }, 2, 2, TimeUnit.SECONDS);
```

## Meter Functions
Right now, only `avg` function has been implemented. I submit this PR as soon as possible to get your feedback. I will add more functions.

## Notice
1. Make slow trace query available in the sampled record. Logically, they are the same thing. The UI doesn't need to concern about the trace as a special case.
2. Endpoint dependency will be removed from the dashboard. Because no query available for it. We will provide a new page for that in 8.1
3. Comparison page will be removed due to dashboard is powerful enough to replace it.

* Add data type to the column definition to replace the simple isValue definition. And top N query is also requiring value column now.

* Support typeOfMetrics query.

1. Support the new query protocol, and the v1 query protocol is still supported 
2. All `numOfxxx`/`GlobalBrief` is only a mock now, no real number.
3. typeOfMetrics service is a mock only too, follow up PR will implement this.

* Set up restrict length rules for service, instance and endpoint

* Adjust two env names.

Here are the list of changes we made in this pull request. Top 3 are the principle changes, others are following these principles.
1. New agent and mesh report protocol. 
2. New agent header protocol. 
3. Service register, instance register and network address register have been removed permanently.
4. Service traffic, instance traffic and network alias metrics are added to replace the service, instance and network address inventory.
5. Register process has been removed.
6. Metrics stream process supports insert only mode, especially for traffic entities.
7. Metrics stream process supports no-downsampling mode for traffic entities and network alias.
8. Remove all register mechanism and cache in the java agent.
9. Remove MONTH step in GraphQL query.
10. Update UI to remove MONTH step query, the max query range is 60 days now.
11. Simplify the TTL to metrics and record. And the unit has been formatted in Day unit. No specific TTL for ElasticSearch storage.
12. Buffer mechanism of trace receiver and mesh receiver has been removed due to no register.
13. New service id, instance id and endpoint id rules, including service relation, instance relation and endpoint relation id rules.
14. Java agent support `keep tracing` mode, meaning, agent generating tracing context even the backend is unconnected/unavailable.
15. Plugin test tool up to date, in order to support new protocol.
16. Plugin tests expected data files updated.
17. E2E tests updated.
18. Telemetry of Grafana config has been merged into one.
19. Documentation updates.
20. [TBD] InfluxDB storage implementation is not available, need @dmsolr to fix later, in order to reduce the master change block by this PR.

- Add length definition with reasonable default value.
- #content of @Column has been renamed to storageOnly . I add this to many fields as they are not being query in any case.
- Merge H2 and MySQL columntype mapping back to consistent.
- Remove @IDColumn.
- Support @QueryUnifiedIndex.
- Refactor the MySQL and H2 installers to use @Column and @QueryUnifiedIndex definitions to create indices automatically. But the index naming rule has been changed to entityseqIDX. seq is the Increment Interger for every entity.
- Support @MetricsExtension and insertOnly in the MetricsPersistentWorker worker.
- Optimize MetricsStreamProcessor

* Finish step one, source and entity changed.

* Step 2, finish the basic and core DAO changes.

* Step 3. Change all source codes of backend, and make project compiling successfully.

* Make startup successful and persistence works.

* Fix dead codes in the MySQLTableInstaller.

* Fix mischange.

* Fix MySQL storage bootstrap error.

* Rollback dependency change.

* Simply enable tailing logs from container no mater it's in CI or not

* Fix segment table issue.

* Fix MySQL Instanller.

* Support Influxdb implementation of new endpoint traffic.

* Set and modify timeout to 90mins

* Remove unnecessary entity in the EndpointTraffic.

* Fix wrong entity builder and make name more clear.

* Fix 2 equal methods bug.

* Fix InfluxDB identifier(name) conflict issue.

* Fix endpoint topology query, endpoint id should be changed as a string.

* Fix a missing change.

* Fix a wrong commit.

* Column name can't be changed, due to it affect the hybrid metadb(h2/mysql) query, change it explicitly with double quotation marks.

* Fix formats.

* Remove endpoint/operation register from the agent. and change the plugin tests(without local tests). operationId relation codes have been removed from agent too.

* Try to fix the hytrix case.

* Fix 3 cases.

* Try to fix cases.

* Fix 2.

* Fix one.

* Fix the serviceId type mis-change.

* Fix int query

* Fix hystrix case.

* Fix a case.

* Fix EndpointCallRelationDispatcher set the source/dest endpoint without id encoding.

* Update documentation and add 2 test cases.
Co-authored-by: Nkezhenxu94 <kezhenxu94@163.com>

* [maven-release-plugin] prepare release v7.0.0

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