[TASK] Write correct error level into `sys_log` table

* PHP exceptions were logged with level "info"
  in the `sys_log` table
* PHP errors were logged with wrong (numeric)
  error level in the `sys_log` table

Only values from `\Psr\Log\LogLevel` are allowed
and usable. Numeric values can not be used or
filtered in BeLog backend module.

Releases: main, 12.4, 11.5
Resolves: #100830
Change-Id: Ie35fe291ac74edd4173e096b8d12609d32c45e02
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79116


Tested-by: core-ci <typo3@b13.com>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>