Add a property to determine the type of a library
Currently pkg-config files have properties which provide building flags for using a project as a shared library and as a static library. But there is no way to determine what type of a library (shared, static or both) some pkg-config file describes.
Because of this some projects have to use workarounds like merging Libs with Libs.private and Requires with Requires.private when the type of an external library is not known. Or the user should manually adjust the type before building a project. See, for example, this PR and references.
I suggest to introduce the property
Type: shared | static | both, which will describe the type of a library. This will allow pkg-config to automatically select right set of flags.