Add automatic links to Sentry issues

Problem to solve

After Sentry integration became available (https://about.gitlab.com/2019/02/22/gitlab-11-8-released/#error-tracking-with-sentry) users are able to see current errors list in Gitlab. However there could be also issues ID in commit messages ("Fixes SENTRYBUG-6F") and it would be nice to have automatic links highlight after integration was set up.

Intended users

Unknown

Further details

Proposal

Make text links in commit text clickable as a link going to original Sentry issue.

Permissions and Security

N/A

Documentation

N/A

Testing

Can be potential conflicts with "Custom issue tracker", needs testing in this area.

What does success look like, and how can we measure that?

Sentry issues IDs are clickable in commit messages.

Links / references