The `--language` option does not work

[erikjv]

The value is read from the command-line options, but it is never used.

The question is if we still need it. It was there before there was the possibility to choose a different language in the UI. So on top of that, do we need the command-line option to override both the UI-configured language and the system language?

See also issue #11142 .

[erikjv]

The value should have been passed to the Application class when it is constructed, and stored in the _userEnforcedLanguage member field (which is currently never set).

[fmoc]

I use it as part of my development cycle in order to start the client with different languages. I think this should be kept.

[HanaGemela]

Removed in ownCloud 6.0.0.12402-daily20231016 ✅
@fmoc please discuss proper implementation of this parameter with @michaelstingl if needed

[fmoc]

We decided on removing it as there are other means of changing the language for testing.