Componentize dagster_gcp resources

[michalcabir-ui]

Summary & Motivation

This PR implements the foundational infrastructure for dagster-gcp Components, enabling YAML-based configuration for Google Cloud resources in Dagster projects.

Used explicit field duplication rather than dynamic field copying. This ensures strict type safety, clear documentation, and avoids runtime surprises(base on what i did on the AWS pr).

Key Design Decisions:

Explicit Pydantic Models: All components (BigQueryResourceComponent, GCSResourceComponent, etc.) explicitly define their fields using pydantic.Field.

GCS: GCSResourceComponent, GCSFileManagerResourceComponent
IO managers: Left out of this PR per review; may be added later.

Dataproc: DataprocResourceComponent (Marked as Beta, strictly enforces required fields like project_id, region, and cluster_name to match the underlying resource).

How I Tested These Changes

I verified the implementation using a comprehensive test suite in dagster_gcp_tests/component_tests/test_gcp_components.py:

Sandbox Integration: Validated full YAML-to-Resource lifecycles using the create_defs_folder_sandbox pattern for all implemented components.

Field Synchronization: Implemented automated tests to ensure Component fields remain a superset of the underlying Resource fields. This ensures that if a Resource adds a field in the future, the test will fail to remind us to update the Component.

Complex Configuration: Verified that DataprocResourceComponent correctly handles complex nested configurations (dictionaries) and required fields.

Changelog

Added foundational Component infrastructure and registry entry points.
Implemented BigQueryResourceComponent, GCSResourceComponent, and GCSFileManagerResourceComponent.
Implemented DataprocResourceComponent (Beta) with support for cluster config dictionaries.
docs: Added a comprehensive MD guide for GCP Components in docs/docs/integrations/libraries/gcp/component.md, updated docs\sphinx\sections\integrations\libraries\gcp\dagster-gcp.rst.

[OwenKephart]

This looks quite close!

Just had a few smaller comments, and a couple small updates to make to the tests

You can just get rid of the IOManager component, I think it's unclear if/how we'll want IOManagers represented in the components system so for now we'll ignore them