Feature: Add support for GitLab releases

[WarheadsSE]

Summary

Bring a parity of functionality to release on GitLab instances.

Details

GitLab has parallel, if not identical functionality for pages and Release artifacts.

After looking through pkg/github/github.go, most of the necessary functionality is present within the glab CLI (links below) to provide the functionality as needed.

Supplementally, GitLab also has support for Helm objects within the package repository. That can be published to via API calls (example in gitlab/gitlab chart's CI here), but is not currently implemented by an existing library call within glab.

Reference

• glab GitLab CLI: https://gitlab.com/gitlab-org/cli
  • glab release sub-command
  • release libraries within the project
• pkg/github implementation

[cpanato]

thanks, i will take a look