Support for Notebooks, SQL assets, and GCS snapshots

A new PipelineConfig schema has been introduced and integrated into CodeCompilationConfig, WorkflowInvocation, and InstallNpmPackagesRequest. This allows developers to explicitly define a pipelineType (DATAFORM, SQL, or NOTEBOOK) and a relative path within the Git repository. Furthermore, the API now supports repository snapshots in Google Cloud Storage for scheduled notebooks, evidenced by new gcsRepositorySnapshotDestination settings in NotebookRuntimeOptions and corresponding metadata in CompilationResult.