A small set of font packages inspired by MyOffice dependencies.

...with the basic bitmap one.

Suggested-by: 9gigabit@gmail.com
See-also: https://bugzilla.altlinux.org/show_bug.cgi?id=34142

zerg@ tells that Obsoletes: is flakey in fonts-ttf-droid
so it's better to specify these three packages instead.

mixin/desktop-installer became *quite* inobvious
even for me over time, and it's not easy to grep up;
let's introduce explicit targets where one is expected
to expect those.

Looks like there are more fonts out there than just croscore!

Font packages are sprinkled all over the metaprofiles,
let's try and help make their use more systematic.

This is a sort of a feature abuse as it was conceived
for fontconfig setup originally but spawning features
with confusing names looks grim; so let all things fonts
live within a feature named "fonts" for the time being.

The issue is that use/fonts/infinality doesn't actually
require the script hook thus registering the feature's
name in FEATURES variable so that the feature's contents
get copied over is not neccessary (distcfg.mk build-up
will have happened anyways).

But that's confusing if one's forgot this peculiarity
(like me today) or never knew of it, so let's spare
some frustration.

Thanks cow@ for both the packages and suggestion.

This includes an updated version of 50-fontconfig script
which actually works (the preliminary one attached to #28612
didn't); thanks zerg@ and cow@ for providing the incentive
to introduce it.

Based on m-p-d and installer-feature-kdesktop-fontconfig.