This adds the following new targets:
- `channel`: A virtual interface for a channel.
- `legacy_channel`: A channel implementation that supports the filter stack and call v2.
- `channel_create`: A standalone function to create a channel.
- `server_interface`: A base class with a few accessor methods used in surface/call.cc.
- `server`: The actual server implementation.
- `api_trace`, `call_tracer`, `server_call_tracer_filter`, `call_finalization`: These were split out of `grpc_base` to avoid various dependency problems.
- `compression`: This is a combination of the previously existing `compression_internal` target and the compression code that was part of `grpc_base`.
Closes#35924
COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/35924 from markdroth:channel_interface 94a7fffddb
PiperOrigin-RevId: 612512438
0213523907