Add editor freelook navigation scheme settings

Depending on what one is trying to achieve, a different freelook mode
may be more desirable.

This closes #34034.

(cherry picked from commit 8a48fb3517)

editor/plugins/spatial_editor_plugin.h

@@ -225,6 +225,12 @@ public:
 		NAVIGATION_MODO,
 	};
 
+	enum FreelookNavigationScheme {
+		FREELOOK_DEFAULT,
+		FREELOOK_PARTIALLY_AXIS_LOCKED,
+		FREELOOK_FULLY_AXIS_LOCKED,
+	};
+
 private:
 	int index;
 	String name;