Define metadata about bundled software modules & base system, next to main application

As a consumer of an AppImage instance I currently miss any information about the additional software bundled with the main application. Same as creator of AppImage instances I miss a specified way to note what is used during the creation. Which can be an issue e.g. when it comes to know if bundled software might have known security issues or when the license of the bundled software requires that its use is made known to the consumer.

So it would be good to have some specified way to notate what ingredients are used, so that this information can be queried for a given AppImage instance.