\Drupal calls should be avoided in classes, use dependency injection instead

@pfrenssen I have made changes in the classes requested and applied dependency injection and removed direct drupal calls and placed construct and create functions where ever needed and updated existing in some of them.
Please review this MR and let me know if there are any changes to be made from my side.

Awesome, thanks so much for working on this. I see there is a test failure, can you have a look? It looks like the introduction of the constructor in WeeklyRecurringDateWidget needs to be adapted to match the parent class.

ok I will make the changes accordingly and make the test pass.

I removed the test failure which was due to mismatch of create function with its parent class.
Please review it and tell me if any changes are to be made

Thanks for the work so far! I did an initial review, I found a few small issues.

Looked there were some phpcs errors. will update once fixed

There are still some direct Drupal calls visible in the PHPStan pipeline.

Made the changes requested, Please review.

Please fix the phpunit pipeline, also there are many warnings in the phpstan which needs to be taken care see: https://git.drupalcode.org/issue/recurring_events-3481021/-/jobs/3724042...

 Method                                                                     
         Drupal\recurring_events\Form\EventSeriesRevisionRevertForm::__construct()  
         invoked with 2 parameters, 3 required.