[Feature request] Gitlab integration

### Description of the issue

It would be nice to have GitLab integration in addition to the existing GitHub integration for task management. This would provide flexibility for users operating on GitLab’s various environments: on-premises, cloud, and SaaS (gitlab.com).

### Your environment

* Version of Huly: latest from https://huly.app
* Browser (and version): Firefox Developer Edition :)

### Steps to reproduce

1. Use task management features linked with GitHub.
2. Attempt to access similar task management features for a GitLab repository.
3. Notice the absence of GitLab as an integration option.

### Expected behaviour

The application should provide an option to link GitLab repositories for task management, similar to the current GitHub integration.

### Actual behaviour

Currently, only GitHub integration is available for task management.

### Possible solutions

GitLab's API ([GitLab API Documentation](https://docs.gitlab.com/ee/api/)) to replicate the GitHub integration for task management.

Review the existing GitHub task-management integration and the GitLab API documentation linked in the issue. Determine the integration entry points and requirements for GitLab on-premises, cloud, and gitlab.com environments. Done means users can link GitLab repositories and access task-management features comparable to the current GitHub integration.

Written by the indexing model from the issue text.