Flag AppStore modules as modified

Best practice is not to modify app store modules, however it still happens quite often one needs to modify an AppStore module.

In the new Mendix 7 modeler App store modules are shown under Project in the Project Explorer, it would like to suggest to automatically move modified AppStore modules or the option to move Modified AppStore modules to a seperate subsection e.g. App store modules Modified

This makes it immediately clear for all developers the module has been modified and shouldn't be overwritten.