Add Spanner DBAPI project #16120

Determine this is the right repository

• I determined this is the correct repository in which to report this feature request.

Summary of the feature request

No response

Desired code experience

file: main.py

   def my_ideal_code():
     ...
     some_data = my_new_feature()
     do_something_with(some_data))

Expected results

e.g. my_new_feature() should return FOO

API client name and version

No response

Use case

e.g. This feature would be useful in a scenario where I need to process large amounts of data efficiently.

Additional context

e.g. This feature would help improve the performance of my application.