Utility methods for Dict needed in the Protobuf/gRPC context.
dictDecoder:Decoder comparable -> Decoder v -> Decoder (Dict comparable v)
Decode a dict from JSON with non-String key type.
This is done by first decoding into a dict/list of key/value pairs with Strings as keys
and then decoding each key while inserting them into a new dict.
Decode a dict from JSON with non-String key type. This is done by first decoding into a dict/list of key/value pairs with Strings as keys and then decoding each key while inserting them into a new dict.