[Task]: Data Sampling

### What needs to happen?

This issue is to track adding a data sampling feature to the SDKs as discussed in the associated [slide deck](https://docs.google.com/presentation/d/1otLNAvI8j41co26UPiIWBFNprnhfnEdJzUXYM2Z0LMw/edit#slide=id.p). This adds:

- The Sample instruction (SampleRequest and SampleResponse) to query the samples from an SDK
- The "beam:protocol:data_sampling:v1" capability to track which SDKs can sample
- The "enable_data_sampling" experiment to toggle the feature
- Automatic sampling in the Python, Java, and Go SDKs for running PTransforms

### Issue Priority

Priority: 3 (nice-to-have improvement)

### Issue Components

- [X] Component: Python SDK
- [X] Component: Java SDK
- [X] Component: Go SDK
- [ ] Component: Typescript SDK
- [ ] Component: IO connector
- [ ] 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