HackStudio: Add HackStudio::for_each_open_file

Author: https://github.com/itamar8910
Commit: 3e9a96f1d8
Pull-request: https://github.com/SerenityOS/serenity/pull/11157
Issue: https://github.com/SerenityOS/serenity/issues/11064

Userland/DevTools/HackStudio/HackStudioWidget.h

@@ -69,6 +69,7 @@ public:
     };
 
     void open_coredump(String const& coredump_path);
+    void for_each_open_file(Function<void(ProjectFile const&)>);
 
 private:
     static String get_full_path_of_serenity_source(const String& file);