gitlab-last-commit.service.js

* Support file path for GitHub last commit

* Support file path for GitLab last commit

* Support file path for Gitea last commit

* Define common `relativeUri` validator

* Sort imports

* Add more tests for path variations

* Fix test name

Co-authored-by: chris48s <chris48s@users.noreply.github.com>

* Update Gitea 404 message

* Handle case when no commits are returned for GitHub and GitLab

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Co-authored-by: chris48s <chris48s@users.noreply.github.com>