Only block form launch during update for Entity-related forms

[lognaturel]

#6440 blocks form launch for all forms when form updates are ongoing. This restriction is only necessary for Entity-related forms.

Some implementation ideas at #6440 (comment)

Acceptance

• Given I have a form that does not access or update/create Entities
  When I start a form update
  Then I should be able to open the form even when the update is ongoing

• Given I have a form that updates or creates Entities
  When I start a form update
  Then I should NOT be able to open the form until the update completes

• Given I have a form that reads Entities
  When I start a form update
  Then I should NOT be able to open the form until the update completes