Fix Drupal 9.0.0 deprecations and test failures

Going to hijack this issue to consolidate all of the D10 compatibility changes.

I approached the deprecated drupal_get_path is a somewhat different way than others. Instead of adding a new service argument to the plugin base class, which potentially breaks compatibility with other plugins that people might have created, I added the moduleExtensionList to the ConfigActions service itself. Plugins then use the new getModulePath function of the ConfigActionService instead of calling the Drupal moduleExtensionList directly.

This saved a lot of mocking and refactoring of tests and I think preserves proper dependency injection.

Uploading the full patch for the test bot.

New patch to fix composer dependency in the test module.

Looks like it can't be tested until this is merged because of composer, so going to merge this into dev and then run tests.

Automatically closed - issue fixed for 2 weeks with no activity.