Enhance translation process

[d4nj1]

As external translations should be integarted faster there should exist some more tooling and guidelines on how to get .po files applied.

DoD:

• Add some validation scripts with google translation integrated
• Add guidelines/workflow/checklist for translations to only create PR for .po files

[fitojb]

Thought of using Weblate?

[d4nj1]

Closed in favor of #121