ARB - remove metadata in the output

[dsavinov-actionengine]

Problem and/or solution

A translated ARB file should only contain the locale, pointing to the translation language (not the source language) and just the key-translation pairs, no other metadata.

How to test

run pytest inside docker exec or via testbed

Reviewer checklist

Code:

• Change is covered by unit-tests
• Code is well documented, well styled and is following best practices
• Performance issues have been taken under consideration
• Errors and other edge-cases are handled properly

PR:

• Problem and/or solution are well-explained
• Commits have been squashed so that each one has a clear purpose
• Commits have a proper commit message according to TEM

[dsavinov-actionengine]

Tagging @kbairak for review