Move I18nQueryTrait from content_translation to migrate_drupal

I think this will be fixed by 📌 Move migration code from content_translation to migrate_drupal Postponed

Added a way to move this to migrate drupal.

This problem is about the source plugins, not migrations so I think we can just move the affected source plugins. I have not done the needed deprecations. I wanted to make sure there were no test failures.

Nice no test failures. Moving to NW for deprecations mentioned in #17

godotislate → changed the visibility of the branch 3258581-move-contenttranslation-i18nquerytrait to hidden.

This is a blocker for 📌 Convert MigrateSource plugin discovery to attributes Needs work , because instantiating reflection on classes that use I18nQueryTrait when content_translation is uninstalled cause a fatal error.

@godotislate, I see you are working on this issue. It is currently assigned to me and I have been working on it locally for a while. :-(

@quietone I completely missed the assigneed. Many apologies.

I've updated the title and unassigned.

Thank you.

I have added deprecations to the moved classes and traits. Do deprecations still need tests? Or is phpstan covering that now?

And again, I apologize to @quietone for missing that you already were working on this and I didn't notice.

@godotislate, no worries. It is just unfortunate that we both were doing the same thing. I think you got there first because I took a break to eat.

Updated per MR feedback.

Maybe it will be less disruptive to move file and provide alias via composer autoloader?

I'm not certain that we can do anything here, but we definitely can't do this. All of these sources being moved are scheduled to be deprecated and removed completely by d12 along with the migrate_drupal module, so we can't set a deprecation message telling people to use the migrate_drupal versions before d12 because those aren't going to exist anymore. I think at best we could introduce a copy of the trait to migrate_drupal and switch the sources over to it without doing any deprecation notices about moving things, and I'm not sure we should bother doing that at this point either.