feat: implement Runner Controller API

Relates to issue #2190

Changes

This MR implements comprehensive support for the GitLab Runner Controller API, adding two new services to the client library.

New Services

1. RunnerControllersService - Manages runner controllers

   • ListRunnerControllers() - List all runner controllers with pagination support
   • GetRunnerController() - Get a specific runner controller by ID
   • CreateRunnerController() - Create a new runner controller
   • UpdateRunnerController() - Update an existing runner controller
   • DeleteRunnerController() - Delete a runner controller

2. RunnerControllerTokensService - Manages runner controller authentication tokens

   • ListRunnerControllerTokens() - List tokens for a runner controller
   • GetRunnerControllerToken() - Get a specific token by ID
   • CreateRunnerControllerToken() - Create a new authentication token
   • RevokeRunnerControllerToken() - Revoke an existing token

Implementation Details

• All endpoints are admin-only (documented in godoc comments)
• Follows existing patterns from cluster_agents.go using the new do function approach
• Uses int64 for runner controller IDs (passed directly to withPath)
• Single type() block for interface and service definitions
• Comprehensive test coverage using testify assertions
• Interface assertions for both services
• Pagination support via ListOptions for list endpoints
• Token visibility handled correctly (token value only in create response)
• Proper HTTP methods (GET, POST, PUT, DELETE)
• Correct terminology: "Delete" for controllers, "Revoke" for tokens

Files Added

• runner_controllers.go - RunnerControllersService implementation
• runner_controller_tokens.go - RunnerControllerTokensService implementation
• runner_controllers_test.go - Tests for controller operations
• runner_controller_tokens_test.go - Tests for token operations

Files Modified

• gitlab.go - Added service fields and initialization for both new services
• gitlab_service_map_generated_test.go - Added service interface mappings
• testing/api_generated.go - Added mock generation directives
• testing/client_generated.go - Added mock fields and instantiations

Note

Documentation is not yet available in the official GitLab API docs. See gitlab-org/gitlab#581275 for tracking.