[TASK] Deprecate various language-related methods and properties

The following methods and properties have been
deprecated:

* Argument $alternativeLanguageKeys in LocalizationUtility::translate()
* <f:translate> ViewHelper argument "alternativeLanguageKeys"
* LanguageService->getLL()

The method "LanguageService->includeLLFile()" is
marked as internal.

This is done in order to streamline future development
in label-related areas.

Resolves: #100721
Releases: main
Change-Id: I1a0bc2eab61ec807cb43082dfef2361dbe6b185f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78799


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>