Add upper sorbian to transcription languages

[zobadaniel]

This is a continuation of this PR: https://github.com/jitsi/jitsi-meet/pull/13925

It includes a simple fix for transcription display if the language code is not 2 letters long, and adds Upper Sorbian (language code "hsb") to the list of supported languages for transcription and translation.

Patch has been tested with release 9220.

[jitsi-jenkins]

Hi, thanks for your contribution! If you haven't already done so, could you please make sure you sign our CLA (https://jitsi.org/icla for individuals and https://jitsi.org/ccla for corporations)? We would unfortunately be unable to merge your patch unless we have that piece :(.

[zobadaniel]

CLA has been signed already some time ago.

[github-actions[bot]]

This PR has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[saghul]

@damencho do you see a problem with this?

[damencho]

Nope