Major Features and Improvements
* Integrated the `CppToPythonExecutorBridge` into the `CPPExecutorFactory`.
* Changed Python Remote Executor to decompose and stream structures in Compute
and CreateValue when _stream_structs is true. Added a bool parameter
`stream_structs` to
`tff.backends.native.set_localhost_cpp_execution_context()` API.
Breaking Changes
* Renamed `tff.backends.native.set_localhost_cpp_execution_context()` to
`backends.native.set_sync_local_cpp_execution_context()`.
* Renamed `tff.framework.ExecutionContext` to
`tff.framework.SyncExecutionContext` to be consistent with
`tff.framework.AsyncExecutionContext`.
* Removed the `SyncSerializeAndExecuteCPPContext` and
`AsyncSerializeAndExecuteCPPContext` classes.
Bug Fixes
* Fixed usage of `typing.Generic` in the learning package.
* Enabled pytype analysis for some modules.
* Fixed lint and formatting issues for some modules.