* Add constants for LUA telemetry
This commit added 896 bytes to flash size which is a significant size. An alternative would to just document the values in the lua telemetry function.
Shortening some of the UNIT names (e.g. UNIT_MW instead of UNIT_milliwatts) or shortening UNIT_ to U_ could save a few bytes but the
* #if 0 ... #endif constants
* horus has 2MB flash