Add claims to ID token to support Fulcio integration

In order to add GitLab as a IdP to Fulcio, we need to add some additional claims to our ID token. The following claims should be added:

Field	Description
ci_config_ref_uri	Fully qualified reference to the pipeline definition, defaults to .gitlab-ci.yml. May point to an arbitrary HTTP remote depending on project configuration.
ci_config_sha	Git commit SHA for the pipeline_ref (only populated when pipeline_ref is local to the GitLab instance).
runner_id	ID of the runner.
runner_environment	The type of runner used by the job. May be one of gitlab-hosted or self-hosted.
sha	The commit revision the project is built for.

See #388517 (comment 1342881271) for more context.

• Consolidate id token claims documentation - !117322 (merged)
• Add runner_id, runner_environment, and sha - !116867 (merged)
• Add ci_config_ref_uri for repository config source - !122373 (merged)
• Add ci_config_sha for repository config source - !124647 (merged)