Add function to obtain filesystem type from DirAccess.

Change EditorFileSystem to not use directory modification times on FAT32, fixes #20946

editor/editor_file_system.h

@@ -231,6 +231,8 @@ class EditorFileSystem : public Node {
 
 	static Error _resource_import(const String &p_path);
 
+	bool using_fat_32; //workaround for projects in FAT32 filesystem (pendrives, most of the time)
+
 protected:
 	void _notification(int p_what);
 	static void _bind_methods();