[WIP] Fill PostgresDB Script for #315

[onegunsamurai]

This script should fill DB with:

• 1000 users (Done)
• 500K Random message trees (WIP)

[andreaskoepf]

I had recommended to use the PromptRepository class. The script as it is now will be outdated in 2-3 days since we will have further change of the DB models, i.e. it creates another dependency that needs to be maintained. Can't merge this as it is.