Adding support for RFC 5424 levels in Logger::toMonologLevel

[Seldaek]

We could support this which would alleviate the need for hacks like https://git.drupalcode.org/project/monolog/-/blob/2.x/src/Logger/Logger.php#L29-50

The numbers do not conflict with the monolog level constants, so this should be fine.

In 3.x we could also have a method on Monolog\Level to turn a case back into a RFC 5424 level.

/cc @lussoluca any opinion from Drupal Monolog side? I think it'd be great to remove the need for overriding methods as it would prevent problems like #1684

[lussoluca]

I agree with you, I can start working on this in the next days