HipChat project service removal

Hipchat was discontinued by Atlassian in 2018, and support reached end-of-life in June of 2020.

We originally planned to remove it in %14.0, but due to #325851 (closed) we had to make it non-operational in %13.11. The gem and some code have been removed in !57434 (merged) and !57556 (merged). There are still some tasks that we have to do:

• Remove HipchatService integration code (model/controller/service/view/api) %13.12 !59769 (merged)
• Remove HipchatService database records from the services table %13.12 !59769 (merged)
• Cleanup remaining HipchatService code %14.0 !62222 (merged)
• Verify product intelligence https://gitlab.com/gitlab-data/analytics/-/issues/8603 and remove YAML files !59000 (merged)

Previous description

We removed this in gitlab-foss#52424 (closed) but it caused some issues as on-prem HipChat is still available. gitlab-foss#60042 (closed) is the issue where we added this back.