[Feature Request]: Add Spanner change stream support to python.

[hughsoup]

What would you like to happen?

Currently Spanner change streams are supported as a source in Java, there is no current support in Python.

Would be great to see this added to the Python SDK.

Issue Priority

Priority: 2

Issue Component

Component: io-py-gcp

[Abacn]

Would be a sub task of #22480

[Abacn]

.remove_labels 'awaiting triage'

[Abacn]

.remove-labels 'awaiting triage'

[brianhlee]

Any plans to add this?

[david-simplehash]

+1 would be a very useful feature. Any plans to add this?

[flpablo]

.take-issue

[Abacn]

Fixed by #35453