[TASK] Streamline labels of site configuration

Labels have been rewritten to consequently use
title case. Additionally, the layout of the
main site tab has been adjusted.

Resolves: #86485
Releases: master
Change-Id: I5186c3a4506d546dc61ef8e4e9e41491b123ace4
Reviewed-on: https://review.typo3.org/58508


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Josef Glatz <josef.glatz@typo3.org>
Tested-by: Josef Glatz <josef.glatz@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>