[Gimp-gui] PLEASE improve font organization

[publicbattery disroot org]

The font selection dialog lacks filtering and grouping features, watch me try to
find a font in a sea of system fonts: https://files.catbox.moe/995uim.webm

In this post I will propose 2 improvements. Font management in GIMP is nothing
short of archaic, but it's not only GIMP's problem, you'll see a lot of people
complain about it in Adobe Photoshop as well.
(https://community.adobe.com/t5/photoshop-ecosystem-discussions/how-to-organize-group-fonts-in-photoshop/td-p/4691695)
One could say indiscriminate alphabetic font lists are a remnant of the older
desktop landscape, where there weren't a lot of installed fonts. Before anyone
tells me to uninstall "uneeded" system fonts, I hope your realise how ridiculous
that is.


1. Automatic grouping. It's true, you already can search for tags, but I have to
apply those tags manually. Every font that GIMP obtains from my system should
automatically have the tag "System" tag. The other folder GIMP looks for fonts
in my system is .config/GIMP/2.10/fonts/. I should be able to only see those
fonts by typing "-System" (negative filtering). Further, I recently downloaded a
font pack for manga scanlation:
    ~/.config/GIMP/2.10/fonts/$ tree -d
    └── scanlation
        ├── Blambot
        │   ├── ACME Secret Agent BB
    ...
        │   └── Zud Juice
        └── Comicraft
            ├── Absolutely Fabulous
    ...
            └── Zzzap

    506 directories, 1592 files

Since these are all under a directory called "scanlation", they should come
tagged with that. The font Zud Juice should come tagged with "scanlation" and
"Blambot".


2. Condense font families in some way: "It would
also be wonderful if GIMP would condense its font list into families instead of
displaying each individual one. Eg, Arial, Arial Italic, Arial Bold, and Arial
Bold Italic could easily be one entry instead of four. Scrolling past a
gazillion fonts just to reach the one I want to use is getting annoying.", 
Snowyn said in Mar 2016: 
(https://mail.gnome.org/archives/gimp-user-list/2016-March/msg00079.html)

I find that the font selection dialog is especially useless if I /don't/ know
what I'm looking for, since 80% of the list is clogged by contiguous blocks of
the same family (with slight differences!), the font selection is a pain in the
ass as "font gallery", it's unusable for "discovery". And I'm sure that if
you're providing font previews then you admit you're not expecting users to know
the precise name of every font they chose. Discovery is an intended element of
the font browser, it's just been always, eh, crap. But it doesn't have to.