Add new error class `QueryCanceled` which will be raised when canceling statement due to user request (#31235)

This changes `StatementTimeout` to `QueryCanceled` for PostgreSQL.

In MySQL, errno 1317 (`ER_QUERY_INTERRUPTED`) is only used when the
query is manually cancelled.

But in PostgreSQL, `QUERY_CANCELED` error code (57014) which is used
`StatementTimeout` is also used when the both case. And, we can not tell
which reason happened.

So I decided to introduce new error class `QueryCanceled` closer to the
error code name.

Since #31129, new error class `StatementTimeout` has been added.
`TransactionTimeout` is caused by the timeout shorter than
`StatementTimeout`, but its name is too generic. I think that it should
be a name that understands the difference with `StatementTimeout`.

This reverts commit 0f79ab91, reversing
changes made to d575f7f2.

This PR philosophically conflicts with #30800 and Matthew thinks we
should hold off merging this until we find concensus. Reverting since
we're about to cut a release for 5.2.

https://github.com/jruby/activerecord-jdbc-adapter ActiveRecord JDBC Adapter is actively developed
and it supports Rails 5.1 now. This pull request addresses one of the failure when running
ActiveRecord unit tests with ActiveRecord JDBC Adapter.

As of right now, ActiveRecord JDBC Adapter supports Rails 5.1, not master branch
then this test only can run on `5-1-stable` branch. But I have opened this pull request to `master` branch
since this type cast should be going to work in the future versions of ActiveRecord JDBC Adapter .

```ruby
$ ARCONN=jdbcmysql bin/test test/cases/attribute_methods_test.rb:203
Using jdbcmysql
Run options: --seed 8874

F

Finished in 0.709120s, 1.4102 runs/s, 1.4102 assertions/s.

  1) Failure:
AttributeMethodsTest#test_read_attributes_before_type_cast_on_a_boolean [/home/yahonda/git/rails/activerecord/test/cases/attribute_methods_test.rb:203]:
Expected: "0"
  Actual: 0

1 runs, 1 assertions, 1 failures, 0 errors, 0 skips
$
```

Use whatever adapter-provided means we have available to ensure forked
children don't send quit/shutdown/goodbye messages to the server on
connections that belonged to their parent.

insensitive

i.e. Oracle database identifier is UPPERCASE unlike other databases.

```ruby
(byebug) query = Developer.all.to_sql
"SELECT \"DEVELOPERS\".\"ID\", \"DEVELOPERS\".\"NAME\", \"DEVELOPERS\".\"SALARY\", \"DEVELOPERS\".\"FIRM_ID\", \"DEVELOPERS\".\"MENTOR_ID\", \"DEVELOPERS\".\"CREATED_AT\", \"DEVELOPERS\".\"UPDATED_AT\", \"DEVELOPERS\".\"CREATED_ON\", \"DEVELOPERS\".\"UPDATED_ON\" FROM \"DEVELOPERS\""
```

`oldie = 'true'` to `tinyint(1)` column is invalid value for MySQL:

```
Mysql2::Error: Incorrect integer value: 'true' for column 'oldie' at row 1: update horses set oldie = 'true'
```

* Add a #populate method to migrations

* Address rubocop issues

* Rename to #up_only and use #execute in the examples intead of the model

* Update CHANGELOG

[Rich Daley & Rafael Mendonça França]

The documentation claims that given values go through "normal AR type
casting and serialization", which to me implies
`serialize(cast(value))`, not just serialization. The docs were changed
to use this wording in #22492. The tests I cited in that PR (which is
the same test modified in this commit), is worded in a way that implies
it should be using `cast` as well.

It's possible that I originally meant "normal type casting" to imply
just the call to `serialize`, but given that `update_all(archived:
params['archived'])` seems to be pretty common, I'm inclined to make
this change as long as no tests are broken from it.

If there are any ignored columns, we will now list out all columns we
want to be returned from the database.

Includes a regression test.

Add new error class `StatementTimeout` which will be raised when statement timeout exceeded (#31129)

We are sometimes using The MAX_EXECUTION_TIME hint for MySQL depending
on the situation. It will prevent catastrophic performance down by wrong
performing queries.

The new error class `StatementTimeout` will make to be easier to handle
that case.

https://dev.mysql.com/doc/refman/5.7/en/optimizer-hints.html#optimizer-hints-execution-time

Follow up of #30360.

`joins_values.partition` will break joins values order. It should be
kept as user intended order.

Fixes #15488.

https://travis-ci.org/rails/rails/jobs/300163487#L1974

Fixes #21577.

Use these to back the attributes API.  Stop automatically including
ActiveModel::Dirty in ActiveModel::Attributes, and make it optional.

use << instead of #concat in #reverse_sql_order because we might be working with Arel SQL literator which overrides #concat

returns true

Not only postgresql or mysql2 adapter, Oracle enhanced adapter
whose default isolation level is read commited, passes these two test cases.

`ConcurrentTransactionTest#test_transaction_per_thread`
`ConcurrentTransactionTest#test_transaction_isolation__read_committed`

```ruby
$ ARCONN=oracle bin/test test/cases/transactions_test.rb:961 -v
Using oracle
Run options: -v --seed 18865

ConcurrentTransactionTest#test_transaction_per_thread = 0.98 s = .

Finished in 1.061036s, 0.9425 runs/s, 5.6549 assertions/s.

1 runs, 6 assertions, 0 failures, 0 errors, 0 skips
```

```ruby
$ ARCONN=oracle bin/test test/cases/transactions_test.rb:979 -v
Using oracle
Run options: -v --seed 13341

ConcurrentTransactionTest#test_transaction_isolation__read_committed = 1.85 s = .

Finished in 1.928637s, 0.5185 runs/s, 10.3700 assertions/s.

1 runs, 20 assertions, 0 failures, 0 errors, 0 skips
$
```

Also, regardless it is a file based or memory based these tests could fail with SQLite3Adapter.
(Extra CR added to make lines shorter)

```ruby
$ ARCONN=sqlite3 bin/test test/cases/transactions_test.rb:961 -v
Using sqlite3
Run options: -v --seed 18815

ConcurrentTransactionTest#test_transaction_per_thread = /home/yahonda/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/sqlite3-1.3.13/lib/sqlite3/statement.rb:108:in `step':
SQLite3::BusyException: database is locked: UPDATE "topics" SET "approved" = ?, "updated_at" = ? WHERE "topics"."id" = ? (ActiveRecord::StatementInvalid)
```

```ruby
$ ARCONN=sqlite3 bin/test test/cases/transactions_test.rb:979 -v
Using sqlite3
Run options: -v --seed 25520

ConcurrentTransactionTest#test_transaction_isolation__read_committed = 0.12 s = E
/home/yahonda/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/sqlite3-1.3.13/lib/sqlite3/statement.rb:108:in `step':
SQLite3::BusyException: database is locked: UPDATE "developers" SET "salary" = ?, "updated_at" = ?, "updated_on" = ? WHERE "developers"."id" = ? (ActiveRecord::StatementInvalid)
```

Ensure that `bin/rails db:migrate` with specified `VERSION` reverts
all migrations only if `VERSION` is `0`.
Raise error if target migration doesn't exist.

A relation includes `klass`, so it can not be used as it is if current
class is different from `current_scope.klass`. It should be created new
relation by current class to respect the klass and STI constraint.

Fixes #17603.
Fixes #23576.