Add Language translation support into Unifier

[NullyIsHere]

Checklist

• [x] The same feedback was not posted yet.
• [x] This is not a suggestion for the moderation team.
• [x] All info applicable to the issue has been attached.

Is your feature request related to a problem? Please describe. I use Unifier self hosted in a Catalan, it would fit better all messages in catalan.

Describe the solution you'd like LangMGR a system plugin that allows you to use new languages in Unifier.

Describe alternatives you've considered *Only Google Translation but this way will have better quality,

Additional context

Related: https://github.com/UnifierHQ/unilang

[greeeen-dev]

Can you edit this to follow the template please?

[NullyIsHere]

Can you edit this to follow the template please?

Done

[greeeen-dev]

thanks

[greeeen-dev]

@NullyIsHere I'm leaving you to finish translation support, I'll be working on adding more stuff to make external platform support better for Unifier