Previous version was prone to the bug:
https://github.com/ruby-concurrency/concurrent-ruby/issues/1075
This is particularly bad cause we could have a DB connection
attached to the thread and we never clear it up, so after N hours
this could start exhibiting weird connection issues.
The custom field "discourse_ai_bypass_ai_reply" was added so
we can signal the post created hook to bypass replying even
if it thinks it should.
Otherwise there are cases where we double answer user questions
leading to much confusion.
This also slightly refactors code making the controller smaller
Roman Rizzi
Sam