Add option/strategy to define package name when exporting

[eMaringolo]

When exporting an application to files we look for the _TONEL_packageName method and use what it returns if it exists or use the application name as the package name.

When dealing with "VAST only" situations, such package name is redundant, and it is often more convenient to only use the app name, without discarding such _TONEL_packageName selector (for future updates coming from an upstream repository).

We need to add an option or a strategy to the TonelWriter to ignore such method and use the app name, such option would be default and included in the #beVASTOnly convenience setup.