Removed locale dirs for single-message apps

Considering that these apps only translate their app name, it's not
worth having a whole bunch of po files just for that. The translatable
app name for those apps will be integrated in Django core catalog.
Revert "Fixed #20477: Allowed settings.FORMAT_MODULE_PATH to be a list of modules."

This reverts commit 950b6de16ac2f8135612f2ed5984c090dd8e4dcf.
Fixed #22652 -- Replaced UserModel.objects with UserModel._default_manager.

Thanks alexdlaird for the report.
Re-added JS catalog in manage_translations script
Updated translation catalogs
Fixed #22655 -- Fixed GeoQuerySet doc about strictly_below

The paragraph was a copy of strictly_above.
Revert "Fixed regression from a2dd618e3b4a7472fab852da450ca5eef92a922f."

This reverts commit 5a2556afb9b1b3ef6e0622552970c67ac84ecd28.
Fix a2dd618 for mysql.
Fixed #22638 -- Changed CookieWizardView to ignore invalid cookies
Fixed #22661 -- Move makemigrations tests to the proper class
Merge pull request #2688 from whoshuu/22661

Fixed #22661 -- Move makemigrations tests to the proper class
Removed unused translations in auth tests
Fixed #22645: Allow apps with no models module to still have migrations
Add feature for implied null (needed for Firebird backend)
Merge pull request #2634 from loic/ticket22424

Fixed #22424 -- MySQL doesn't accept migrations' one-off default values ...
Fixed #22649: Beefed up quote_value
Fixed #22432: SQLite M2M repointing now works. Thanks to xelnor.
Revert "Fixed #22645: Allow apps with no models module to still have migrations"

This reverts commit a4737bf6ae36a5f1cb29f2232f6deeff084fabff.
Fixed #22557 -- ManifestStaticFilesStorage did not cleanup deleted files.

When using ManifestStaticFilesStorage, deleted static files would be
correctly cleaned up by "collectstatic --clear", but the manifest file
would still contain the stale entries.

Thanks to tedtieken for the report
replaced occurrences of master/slave terminology with leader/follower