feat(sat): point the antenna — EasyComm II az/el rotator

EasyComm is what satellite rotator controllers agreed on, so a box that
works with SatPC32, Gpredict or Hamlib works here. Serial or TCP, and its
own settings rather than the HF rotator's: an az/el pair is a different
machine on a different port, and an operator who has both must not have
to choose.

A great many EasyComm controllers — the Arduino trackers above all —
accept commands and never say a word back. That is legal and common, so a
silent controller is not treated as a broken one: it is still driven, and
the last commanded position is reported in its place, marked as commanded
rather than read. A stuck rotator must not be able to hide behind an
order it never carried out, which is why the panel shows the antenna's
position beside the satellite's.

The 450° overlap is the reason a satellite rotator is worth having, so it
is used: a pass crossing north continues past 360 instead of unwinding
three quarters of a turn with the antenna sweeping the ground. Below the
configured elevation the mast is left alone — the numbers are right all
the way round the orbit, but a rotator that chases a satellite through
the far side of the earth spends the night turning, and a mast has a
finite number of turns in it.

frontend/wailsjs/go/main/App.d.ts

@@ -1429,6 +1429,8 @@ export function TestQRZUpload():Promise<string>;
 
 export function TestRotatorDevice(arg1:main.RotatorDevice,arg2:number):Promise<void>;
 
+export function TestSatelliteRotator():Promise<string>;
+
 export function TestStationDevice(arg1:main.StationDevice):Promise<main.StationTestResult>;
 
 export function TestUltrabeam(arg1:main.UltrabeamSettings):Promise<void>;

frontend/wailsjs/go/main/App.js

@@ -2790,6 +2790,10 @@ export function TestRotatorDevice(arg1, arg2) {
   return window['go']['main']['App']['TestRotatorDevice'](arg1, arg2);
 }
 
+export function TestSatelliteRotator() {
+  return window['go']['main']['App']['TestSatelliteRotator']();
+}
+
 export function TestStationDevice(arg1) {
   return window['go']['main']['App']['TestStationDevice'](arg1);
 }