Create new gitlab module for scorecard

Scorecard is a backstage plugin and supports multiple metric, grouped as modules in folder workspaces/scorecard/plugins.

There are already modules that support GitHub, OpenSSF, SonarQube. Add a new module for GitLab, called gitlab.

Similar to the github module it should use the existing Backstage scm configuration for gitlab.

All metrics providers should filter for entities with annotation gitlab.com/project-slug.

For these entities it should call the GitLab API to populate these metrics.

These for issues and merge requests:

1. Open issues (current count)
2. Opened issues that was opened in the last 7 days
3. Closed issues that was closed in the last 7 days
4. Open merge requests (current count)
5. Opened merge request that was opened in the last 7 days
6. Closed merge requests was was closed or merged in the last 7 days

These for pipelines and jobs:

7. Number of started pipelines and jobs in the last 7 days.
8. Number of successfully finished pipelines and jobs in the last 7 days. Ignore these which are pending, running, canceled, etc.9, Number of failed pipelines and jobs in the last 7 days. Ignore these which are pending, running, canceled, etc.
9. Two metrics for Ratio of successful vs successful+failed pipelines and jobs, once for the last 7 days and one for the last 24 hours. Ignore these which are pending, running, canceled, etc.