fix: set application policy on macOS for extension (#6043)

src/util/MacOsHelpers.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void chatterinoSetMacOsActivationPolicyProhibited();

src/util/MacOsHelpers.mm

@@ -0,0 +1,9 @@
+#include "util/MacOsHelpers.h"
+
+#include <AppKit/AppKit.h>
+
+void chatterinoSetMacOsActivationPolicyProhibited()
+{
+    [[NSApplication sharedApplication] setActivationPolicy:NSApplicationActivationPolicyProhibited];
+}
+