IOS/ES: Implement ES_SetUid

This implements ES_SetUid, which is used by the system menu to change
its own permissions. This is required for implementing permission
checks and proper NAND metadata support in the future.

Source/Core/Core/State.cpp

@@ -71,7 +71,7 @@ static Common::Event g_compressAndDumpStateSyncEvent;
 static std::thread g_save_thread;
 
 // Don't forget to increase this after doing changes on the savestate system
-static const u32 STATE_VERSION = 80;  // Last changed in PR 5309
+static const u32 STATE_VERSION = 81;  // Last changed in PR 5317
 
 // Maps savestate versions to Dolphin versions.
 // Versions after 42 don't need to be added to this list,