n64: Unload and save before reset() on gamepad and disk (#1464)

7ad14ff6bf
inadvertently made it so that .pak saves (and other save data) are not
properly persisted to disk when unloading the n64 core. This PR resolves
that, calling `unload()`, which itself calls `save()`, before resetting
the gamepad and other memory.

Co-authored-by: jcm <butt@butts.com>

desktop-ui/emulator/nintendo-64.cpp

@@ -193,11 +193,12 @@ auto Nintendo64::load(Menu menu) -> void {
 }
 
 auto Nintendo64::unload() -> void {
+  Emulator::unload();
+
   gamepad.reset();
   disk.reset();
   gb.reset();
 
-  Emulator::unload();
   diskInsertTimer.reset();
 }