* Fix REST some rest call signatures and implement a simple API benchmark tool
* Implement #3129 (Optimized history traversals in the REST API)
Other notable changes:
The `updateStateData` procedure in the `blockchain_dag.nim` module is
optimized to not rewind down to the last snapshot state saved in the
database if the supplied input state can be used as a starting point
instead.
* Disallow await in withStateForBlockSlot