TYPO3 Core

This is a "follow up" of #91381. The issue here lists other feedback systems we can implement to warn the integrator accordingly.

• Automatically add the Redirect finisher to the end in the form editor GUI and keep it there even on finisher redordering
• Refactor the code to actually execute the finisher only at the end of the request after all other finishers (this might require new API since 3rd party code will need this too)
• Show and/or log a warning if such a form is rendered (this covers hand-written form definitions)