TensorFlow Federated 0.48.0

Release 0.48.0

Major Features and Improvements

• Implemented divisive split logic needed by DistributeAggregateForm, which is
  currently under development and will replace MapReduceForm and BroadcastForm
  in the future.

Breaking Changes

• Renamed the cpp_execution_context.(create|set)_local_cpp_execution_context
  function to match the name of
  execution_context.(create|set)_(sync|async)_local_cpp_execution_context.
• Deleted the sizing Python execution context and executor.
• Deleted the thread debugging Python execution context and executor.
• Removed ExecutorService from the public API.
• Deleted the local async python execution context.

Bug Fixes

• Enabled and fixed python type annotations in some modules in the
  executors, types, and core package.