[client] recovery: add force keybind

Add a configured escape key plus Shift+R command that requests display
recovery from the LGMP transport and switches video to SPICE.

Track the request on the main thread, report its asynchronous result,
and return its producer instance with the request serial for exact
correlation.

Preserve normal escape+R rotation behavior, including custom Shift
escape keys.

client/transports/LGMP/lgmp.c

@@ -1420,7 +1420,7 @@ static LG_TransportStatus lgmp_getRecoveryInfo(LG_Transport * this,
 }
 
 static LG_TransportStatus lgmp_requestRecovery(LG_Transport * this,
-    LG_RecoveryRequest request, uint32_t * serial)
+    LG_RecoveryRequest request, uint64_t * instance, uint32_t * serial)
 {
   uint32_t wireRequest;
   switch (request)
@@ -1505,6 +1505,8 @@ static LG_TransportStatus lgmp_requestRecovery(LG_Transport * this,
   }
   if (serial)
     *serial = ticket;
+  if (instance)
+    *instance = header.session;
 
   LG_UNLOCK(this->recoveryLock);
   return LG_TRANSPORT_OK;