[BUGFIX] Make widget group identifier unique

In the "Add widget" dialog the id of the group tab was not unique.
This interfered with other ids in the backend. A prefix was added
to make it unique.

Resolves: #91129
Releases: master
Change-Id: Icf528c6ff8d755470d3158e94b1916a5ce028981
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64248


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>