[TASK] Unify position for docheader buttons

Buttons in button groups either had space between them or were glued
together, because they used to be in the default button group.

The buttons are now separated into different button groups to unify
their positioning.

Resolves: #99247
Releases: main
Change-Id: I418a0d81538e4890e066ac643a9d140e21436b5f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76882


Reviewed-by: Annett Jähnichen <mcmietz@web.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Annett Jähnichen <mcmietz@web.de>