Add NominalPower

[upcu]

Based on New Unit added: Nominal Power by @McGum

[angularsen]

Thanks for the contribution! A couple of things need to be fixed in NominalPower.json:

1. Missing BaseDimensions

NominalPower is dimensionally equivalent to Power (W = kg·m²/s³). The quantity definition needs BaseDimensions, same as Power.json:

"BaseDimensions": {
  "L": 2,
  "M": 1,
  "T": -3
}

2. Missing BaseUnits on WattPeak

The WattPeak unit needs BaseUnits to map to SI base units, same as Power.json's Watt:

"BaseUnits": {
  "L": "Meter",
  "M": "Kilogram",
  "T": "Second"
}

Please add these and the PR should be good to go!

[angularsen]

Please don't change generator code unless intentional

[angularsen]

Should we rename this to disambiguate this from other kinds of nominal power?
It seems maybe a bit ambiguous: https://en.wikipedia.org/wiki/Nominal_power

For example, NominalPowerPhotovoltaic