Surface project webhook owner and allow webhook management

[gtsiolis]

Problem to solve

Adding a project and enabling prebuilds requires:

• Maintainer user role for GitLab, see relevant docs.
• Admin user role for GitHub, see relevant docs.
• Administrator role for Bitbucket, see relevant docs.

It's currently not visible who installed a webhook for a project.

There's also not sufficient feedback on the dashboard that the webhook has been uninstalled or the user who add a webhook no longer exists, see #12414.

We've also heard some feedback that some users don't want to enable prebuilds for a repository, which could make room for a use case where enabling prebuilds is optional, see #15281.

Proposal

Surface project webhook owner and allow webhook management.

This could include the user information who installed the webhook in project settings, but also allow managing (removing, reinstalling) the webhook.

TBD (To be discussed)

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[gtsiolis]

Closing in favor of EXP-344.