feat(developer): extract font family from .ttf in kmc-keyboard-info

Instead of generating a name for the web fonts, we should be using the
font family from the .ttf, as we have it available. This allows us to
avoid downloading the font if the user already has it installed on their
system.

Uses ttfmeta npm package, which is a lightweight .ttf reader. Updates
the honking big unit test to do some basic tests on this functionality.