### What problem does this PR solve?
Currently, if we want to restrict the allowed factories users can use we
need to delete from the database table manually. The proposal of this PR
is to include a variable to that, if set, will restrict the LLM
factories the users can see and add. This allow us to not touch the
llm_factories.json or the database if the LLM factory is already
inserted.
Obs.: All the lint changes were from the pre-commit hook which I did not
change.
### Type of change
- [X] New Feature (non-breaking change which adds functionality)
3654ae61c1