Font provider service

Fuchsia offers a discoverable protocol called fuchsia.fonts.Provider for requesting font assets.

A client may obtain a digital font file for a font family with Provider.GetTypeface(), which specifies query parameters, as well as fallback and match logic. If satisfiable, the method returns an appropriate font file buffer and some metadata.

The client may also query the styles available within a font family, with Provider.GetFontFamilyInfo().