Remove HipChat integration from GitLab

What does this MR do?

Removes the HipChat project service integration.

• One controller spec needs distangling from HipChat reliance: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/23774
• Remove errant rows in the database
• Prevent project exports containing hipchat services from becoming invalid

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides

Closes #52424 (closed)