[TASK] Modernize ext:belog

* Use strict function argument and return types where possible
* Removed superfluous argument and return type doc comments
* Replaced deprecated strftime usage
* Removed invalid extension key for LocalizationUtility usage
* Replaced switch statement with match expression
* Removed superfluous type casts

Resolves: #98184
Releases: main
Change-Id: If2f4060f80f26c2116eb668220d009b7ae4281b1
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75527


Tested-by: core-ci <typo3@b13.com>
Tested-by: Susanne Moog <look@susi.dev>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Benni Mack <benni@typo3.org>