Feature request or enhancement

Which use case/requirement will be addressed by the proposed feature?

Currently, the Debezium Server Pub/Sub connector does not provide a way to specify Google Cloud Pub/Sub locational endpoints in production environments. While `debezium.sink.pubsub.address` can be specified, this is intended for development or test environments with emulators and is not suitable for production use with regional endpoints as it uses plaintext communication without encryption. 

This feature request aims to address the following use cases:

• When using ordering keys with Pub/Sub, messages must be processed in the same region to guarantee order. The current global endpoint connection relies on automatic routing to the nearest region, which cannot be 100% guaranteed.
• Organizations with specific compliance, data residency requirements, or message storage policies with `enforceInTransit=True` need direct control over which regional endpoints process their Pub/Sub messages. Without explicit endpoint specification, requests may be rejected if initially routed to non-allowed regions.

refs:

https://cloud.google.com/pubsub/docs/ordering

https://cloud.google.com/pubsub/docs/resource-location-restriction

Adding locational endpoint support would allow direct connections to regional endpoints (e.g., us-central1), bypassing the uncertainties of global endpoint routing.

Implementation ideas (optional)

Add a new config parameter `debezium.sink.pubsub.locational.endpoint` that accepts a Google Cloud region name (e.g., `us-central1`). When specified, Debezium Server would construct and use the appropriate regional endpoint URL (e.g., https://us-central1-pubsub.googleapis.com/) instead of the global endpoint.