* add tests for fetching key locally
* add logic to check if origin server is same as host and fetch verify key locally rather than over federation
* add changelog
* slight refactor, add docstring, change changelog entry
* Make changelog entry one line
* remove verify_json_locally and push locality check to process_request, add function process_request_locally
* remove leftover code reference
* refactor to add common call to 'verify_json and associated handling code
* add type hint to process_json
* add some docstrings + very slight refactor
