Use FPP/JSON instead of XMLs

[Lex-ari]

Update for v4 of F′ nasa/fprime#4538

Currently, fprime-python parses XMLs to get commands, events, telemetry, ports, etc to autocode for a python component. Fprime-python should be updated to read from FPP, JSONs (generated from FPP), or perhaps a templated hpp in order to create the appropriate python functions.