Create a solution to merge and cleanup vocabularies tables

After NXS-4206 , we have to create a solution to clean its consequences for affected customers.

Backends for solution

• PostgreSQL

Solution should:

1. Get studio vocabularies list by retrieving the studio_vocabulary* tables
2. Check for each vocabulary if a table exists with the vocabulary name and appropriate structure (unprefixed) => if it doesn't, continue with next vocabulary
3. When both tables exist:

• Copy new entries into prefixed table
• Conflicting entries (same id in both tables) should be added to a log file with a mention: "[Date and time] - [vocabulary name] - entry [id] [label] could not be merged due to a conflict."

When merge is over, add an entry in the logs with:

• "[Date and time] Finished merging [number of vocabularies] Studio vocabularies. To finish cleanup, delete the associated unprefixed tables by running the SQL query below."
• the SQL command to run in order to delete the unprefixed tables so that user can check result and delete tables when ready for it