Backend: Link to GitLab commit in error detail page

What does this MR do?

This MR adds the gitlab_commit to the error detail endpoint. This is intended to roughly identify what commit introduced an issue by using the commit that the release is versioned with to match on any of the commit shas from the repo.

Backend for #38223 (closed), please see the spike for more discussion on why we decided to match on the release version.

Technical Implementation

Added the first_release_version to the sentry client but not the gitlab_commit since the sentry client should only be responsible for getting data from sentry.

Added a post processing step to the error tracking settings model after the data is fetched from sentry which adds the gitlab_commit the issue_details result.

Screenshots

Does this MR meet the acceptance criteria?

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

Added a tests for issue_details for when a commit does or does not match.

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