Refactor Django upgrade commands

[nutjob4life]

Now that we've transition from Plone to Wagtail (version 6.0), and done two post-conversion upgrades (6.1 and 6.2), I'm noticing a pattern in the Django upgrade commands that produces a lot of repetition and boiler-plate code.

This primarily has to do with each upgrade command having to

• Save the current state of Wagtail automatic redirection creation
• Disable Wagtail automatic redirection creation
• Save the current state of Wagtail indexing
• Disable Wagtail indexing
• Then, finally, execute the command
• And, whether it succeeds or not:
  • Restoring the state of Wagtail indexing
  • Restoring the state of Wagtail automatic redirection creation

To reduce the lines of code and decrease the chance of error, these steps should be refactored into a common superclass for P5-specific Django upgrade commands.