Closes #23934.

This is a forward port of ac832a43

Previously the scope of all associations with extensions were wrapped in
an instance dependent proc. This made it impossible to preload such
associations.

Change 'a HTTP' to 'an HTTP' [ci skip]

Niceify the dynamic routes deprecation messages

Change 'a HTML' to 'an HTML' [ci skip]

ConnectionMonitor is once again notified of disconnect

Follow-up to #23980.

- Fix grammar: "be remove" -> "be removed".

- Wrap lines at 80 chars.

Lurvely ;-)

Changed behaviour of timestamps helper by create_table migration generator [ci skip]

Fix a small template misrender in ActiveRecord::Persistence

See the end of [this] page.

[ci skip]

[this]: http://edgeapi.rubyonrails.org/classes/ActiveRecord/Persistence/ClassMethods.html#method-i-create

Deprecate `{insert|update|delete}_sql` in `DatabaseStatements`

This reverts changes made to integration tests in PR #23807.
The issue happens when using capybara with a driver that needs to start a
server in a separate thread like (poltergeist, selenium, etc).
Both threads the capybara server one and the test thread end running
syncronize over the interlock.

[ci skip] Add `bundle exec` for ActiveRecord unit tests

Fix description in cookies_serializer.rb being corrupted by gsub when updating

Fix typo in app_generator_test.rb

Fix typo in implicit_render

Remove not needed `exec_insert` in mysql2 adapter

 [ci skip] Use rails routes instead of rake routes in inspector test …

Accept channel identifiers with no backslashes/escaping

Fixes #22675

Allow channel identifiers and also data with no backslahes/escaping to be accepted by
the subscription storer.

When trying to make a request and the request doesn't have a suitable template, the new error messages are really helpful but there's a small (and I mean, VERY small) typo that has been bugging me for the last few days. This adds the space and restores order to the universe. ❤

ActionCable: Add a "welcome" and "ping" message type

Remove requiring load_paths from tools/test.rb

- Instead require and setup Bundler
- `tools/test.rb` is used internally from all `bin/test` scripts inside
   component gems.
- Followup of https://github.com/rails/rails/commit/2abcdfd978fdcd491576a237e8c6be04ddaf884d.

Originally, `{insert|update|delete}_sql` is protected methods.
We can use the `{insert|update|delete}` public methods instead.

Simply it is sufficient to use the method in the super class.

Fix `ActiveSupport::Reloader.check!`

The test failure in `bug_report_templates/action_controller_master.rb`
is due to `app.reloader.check` is `nil`.

Remove load_paths file