* Add type for GitLab ProvisionToken
* Add default behaviour for domain
* Add IDTokenClaims for GitLab
* Add gitlab token source and token validator
* Thread GitLab support through auth and tbot packages
* Adjust cluster name fetching in token validator
* Initialize GitLab token validator in auth
* Improve comment on `sub`
* Working GitLab CI delegated joining
* Add additional token rule fields
* Add checking for new configuration fields
* add additional test cases for validation of gitlab config struct
* Add TestAuth_RegisterUsingToken_GitLab
* Add tests for IDTokenSource
* Fix imports
* Add tests for GitLab Token Validator
* Fix some comments that were incomplete
* Add license headers
