[Feature] Add Action Text uninstall to remove copied migration and files.

[Abhay Nikam]

Hi folks,

I have been playing a bit with Action Text a lot lately and recently we have switched Action Text install to a generator in PR: https://github.com/rails/rails/pull/35085

We could now use the generator to destroy the added files as well. Will it be a good idea to add a `bundle exec rails action_text:uninstall` to remove the copied files? 

I would love to work on it and raise a PR if anyone is interested.

Thank you for your time!