#1532 - Add upgrade message about civicase activity revisions

APIv4 - Add `case_id` field to Activity entity

Remove another three no-longer-used functions

Fix use of legacy pseudoConstant methods

Remove no-longer-used function

Case-insensitive match on subtypes when validating subtype by entity for custom groups

SettingsStyleTest - Stop the madness

[Import] [Ref] Extract shared form rule code

[NFC] Add test for editing activity subject to file on case

This moves processCaseActivity call out of APIv3 and into the BAO where it can be re-used by APIv4.

This virtual field allows an activity to be easily filed on a case,
and for cases to be looked up in SearchKit activity searches.

Add hint to create membership "You do not have all the permissions needed for this page" message

5.53

#3802 - Compatibility with symfony 6 for drupal 10 for listeners added via getSubscribedEvents

[NFC] Convert Payment Processor ID field to payment processor in even…

#1532 - Remove civicaseActivityRevisions setting & related code

Remove unused impossible function in upgrade page

This setting has been deprecated for years, and core CiviCase doesn't respect it
anyway. Only the API was really paying attention to it. Time to get rid of that stuff
as a preamble to ripping out all of the case activity revisioning.

This exception is *also* raised, when no membership types have been configured yet, which can be very confusing. It cost me a two hours to figure out the real reason, and I have the nagging suspicion that this had happened to me before. I'm not too happy about the phrasing, but it would be good to have a reference to a potentially incomplete configuration. Thanks.

Fix processCaseActivity docblock

[REF] Activity BAO - Decouple CiviCase logic from create function

A big chunk of civicase code was jammed into the Activity create function.
This moves it to the Case BAO.

NFC - Make it possible to mark a dao field @deprecated

Resolve existential crisis for customfield.is_active

5.53