[Feature Request]: Request Response IO for Python SDK

[riteshghorse]

What would you like to happen?

Implement a request response IO to interact with REST APIs/GRPC in beam pipeline. This should be in parity with the Java implementaion tracked by #28934

Issue Priority

Priority: 2 (default / most feature requests should be filed as P2)

Issue Components

• Component: Python SDK
• Component: Java SDK
• Component: Go SDK
• Component: Typescript SDK
• Component: IO connector
• Component: Beam YAML
• Component: Beam examples
• Component: Beam playground
• Component: Beam katas
• Component: Website
• Component: Spark Runner
• Component: Flink Runner
• Component: Samza Runner
• Component: Twister2 Runner
• Component: Hazelcast Jet Runner
• Component: Google Cloud Dataflow Runner

[riteshghorse]

Progress Tracking:

• Python bindings for Mock API to test the IO
• Caller class interface
• Cache PTransform (Read/Write)
• Integration Test
• Example

[riteshghorse]

#30307 has the cache support and integration test