CU-8695x1dy9: Changes for running predictions async in a bg process

[tomolopolis]

These changes enable:

• running models in background process,
• run process_tasks in separate docker compose service
• add a dialog workflow to inspect running state of bg_process
• add an API to cancel running process and directly go in to annotate a project.

Bug fixes

• CSRF_TRUSTED_ORIGINS empty env var wasn't being processed correctly to not raise a warning, now fixed
• Model_cacheing - new env var to clear down models in the module level cache. This is set to 2 by default

[tomolopolis]

Task linked: CU-8695x1dy9 ability to load predictions for all documents in a background process