[BUGFIX] Render proper markup for datetime picker buttons

To make datetimer picker buttons focus the belonging textfield, the
buttons were rendered as `<label>` which is a very dirty hack, leading
to clitching buttons.

To solve this, the `@typo3/backend/global-event-handler` module is now
capable of focussing a specific element after clicking a trigger
element.

Resolves: #98054
Releases: main, 11.5
Change-Id: I828785267e6a8c25f3ed7c17221e903cd4cc3220
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75331


Tested-by: core-ci <typo3@b13.com>
Tested-by: Riccardo De Contardi <erredeco@gmail.com>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>