feat: quick connect for RDP and VNC (#1335)

The Quick Connect panel gets a protocol switch. RDP/VNC quick hosts are
built like SSH ones (never saved) and opened as regular remote desktop
tabs; GuacamoleApp mints their token from the typed fields through the
existing /guacamole/token endpoint instead of a host-row lookup.

src/ui/locales/en.json

@@ -3686,6 +3686,11 @@
         "privateKeyPlaceholder": "Paste private key...",
         "credentialLabel": "Credential",
         "credentialPlaceholder": "Select a saved credential",
+        "protocolLabel": "Protocol",
+        "domainLabel": "Domain",
+        "domainPlaceholder": "optional",
+        "connectToRdp": "Connect via RDP",
+        "connectToVnc": "Connect via VNC",
         "connectToTerminal": "Connect to Terminal",
         "connectToFiles": "Connect to Files"
       },