Fixes #4909
### Motivation

It would be good to expose method `getLastMessageId` in `ConsumerImpl` to a public method. 
eg. some times user would like to know the lag messages; or only consume messages before current time.

### Modifications

- expose method `getLastMessageId` in consumer api.
- add unit test.

### Verifying this change
Ut passed

(cherry picked from commit 93d95c74)

* Simplified assert statements in the tests. Switch to usage of static imports in tests. (Part 1)

* Simplify assert statements in the tests and use the appropriate assert statements. Switch to usage of static imports in tests. Remove unused imports (Part 2)

(cherry picked from commit fb6895db)

* change getTopicName in MultiTopicsConsumer

* change following sijie's comments

* keep both topicName and topicPartitonName in consumer to avoid new string

*Motivation*

Fixes #1918

*Solution*

Make sure `MessageIdImpl` and `BatchMessageIdImpl` recognize TopicMessageIdImpl

* Refactored all unit tests to use new typed API with builders for configuration

* Did conversion in pulsar-client tool

* Refactoring typo fixes

A batch message id is a MessageIdImpl with a batchIndex >=
0. Therefore, they can be compared to MessageIdImpl. If all fields
other than the batchIndex are equal to a messageId, the
BatchMessageIdImpl can compare its batchIndex with -1. If it is -1, it
matches the MessageIdImpl. If it is greater than -1, then it is
greater than the MessageIdImpl.