fix: #3591145 Fix geofield_google_map Views style schema

This MR fixes remaining config schema errors for the geofield_google_map Views style.

It updates the Views style schema so it matches saved configuration for:

• data_source
• Entity Type - Image Select map theming values
• the saved map themer id and description values

I tested this locally on Drupal 11.3.9 with Geofield Map 11.1.9. Before the change, saving the affected View reported schema errors for data_source and geofieldmap_entity_type_url settings. After applying this schema change and rebuilding caches, the View saved without schema warnings.

AI-Generated: Yes (Used OpenAI Codex to inspect the schema errors, prepare the schema update, and test the change locally.)