fix(#1623): Move querying metadata-validation to frontend service

[MSzalowski]

Summary

Haskell backend should be responsible only for fetching the DB-sync data. So I moved the querying the metadata-service logic to frontend that can consume 2 backends with ease and later on - react on socket events when appropriate designs on the cards are done.
That operation helps in decreasing the complexity level in Haskell backend making it easier to track and investigate errors around faulty SQL (#ref) or Thread killed by timeout issues - #1417

List of changes

• Move metadata-validation service requests to frontend service

Checklist

• related issue
• My changes generate no new warnings
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the changelog
• I have added tests that prove my fix is effective or that my feature works

[MSzalowski]

After much time on investigation this issue I decided to not include fix for that in that PR and provide metadata from validation service once validated.

[MSzalowski]

This PR is the solution candidate as it introduces breaking change to the infrastructure.
I'll make more investigation around #1650 before merging this one.

[placek]

LGTM