[BUGFIX] Always set last checked in multi record selection

Since #94944 the multi record selection allows
keyboard shortcuts for an improved UX. It's
for example possible to select ranges. Therefore,
the last checked element and the current target
are used to determine the range.

Any operation in case no valid shortcut is used.
This however prevents the last checked element
from being set. As a result the range determination
did not longer work reliably.

This is fixed by moving the shortcut check into
the already existing guard clause, which does
properly set the last checked element.

Resolves: #95060
Related: #95034
Releases: master
Change-Id: Ibc1c2fdc314b58af3848a4934d1f5e0124de2e55
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70847


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>