Add gitlab_commit_path to Sentry Error Details Response

What does this MR do?

This adds the gitlab_commit_path to a sentry error so that the front end does not need to know about the path. I chatted about this with @syasonik, and we both agreed that it would be ok to use the view helpers in a model in this case because otherwise we won't be efficient about requesting data (requesting the same service twice - once for the html page and once for the json format).

See discussion here:

!22431 (comment 269044981)

!22431 (comment 266992397)

Conformity

• [-] Changelog entry
• Documentation (if required)
• [-] Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers