fileapi: consider exporting interface properties/exports in target info
There are use cases where retrieving the information available from the interface target properties/exports would be useful. For example, a tool using this information can produce CMake-agnostic export files (for example, pkg-config, or other alternatives). Or package managers like Conan that want to understand the properties of exported targets to make them accessible to non-CMake package consumers can get this information directly from CMake, instead of duplicating it manually in the package recipes.
Is the file API appropriate for getting this information? Can such extension be considered?
Currently the API has all the targets (except the INTERFACE ones, but I assume that will eventually change) and some install-rule information, but no information on target's EXPORT_NAME association, and no way to get to the interface properties of an exported target.