feat(worked): fold portable callsigns into the worked-before history

Typing RK3DWA found nothing while RK3DWA/3 found 21 QSOs, so a station's
history was only visible if you happened to type the exact form it had been
logged under — and an operator who worked it as /0, /P or /MM saw none of it.
The other RDA tools and Log4OM fold these together; this does too.

The predicate strips the suffix from what was typed and matches "call = base OR
call LIKE base/%", so it works from either end: the base call finds the portable
QSOs and a portable call finds the plain ones. Deliberately not a bare prefix
LIKE 'RK3DWA%', which would also match RK3DWAB — a different station. The '/' is
what makes it the same operator.

Settings -> General to turn it off. Default ON, hence the inverted storage: an
existing install has no key, and reading that as OFF would leave everyone with
the behaviour we were asked to change.

Contest dupe checking is untouched — it runs through ContestDupe, a separate
binding, and stays an exact match as a contest requires.

frontend/wailsjs/go/main/App.js

@@ -978,6 +978,10 @@ export function GetWinkeyerStatus() {
   return window['go']['main']['App']['GetWinkeyerStatus']();
 }
 
+export function GetWorkedCallVariants() {
+  return window['go']['main']['App']['GetWorkedCallVariants']();
+}
+
 export function GetYaesuState() {
   return window['go']['main']['App']['GetYaesuState']();
 }
@@ -1882,6 +1886,10 @@ export function SetWinkeyerTrace(arg1) {
   return window['go']['main']['App']['SetWinkeyerTrace'](arg1);
 }
 
+export function SetWorkedCallVariants(arg1) {
+  return window['go']['main']['App']['SetWorkedCallVariants'](arg1);
+}
+
 export function SetYaesuAFGain(arg1) {
   return window['go']['main']['App']['SetYaesuAFGain'](arg1);
 }