Dropping Hildon unless a maintainer steps up

3 months ago I made #286 (closed), indicating that Hildon doesn't have a maintainer. Still maintained upstream (just a few people working on it), but basically useless in postmarketOS without more stuff packaged as listed in #234 (closed).

After a discussion with the team, we've decided to make this issue, and if no one within a month steps up to maintain it, I'll make a MR to drop it from our repositories. If still no one steps up within a week, we'll merge it. Do note stepping up to be a maintainer of this UI means you will need to eventually package everything in #234 (closed) and make it properly usable.

I was thinking of being a maintainer myself originally but I'm not interested enough and rather spend my time on other UI's like Plasma Mobile and Phosh. I did however do a bunch of work towards #234 (closed) already, and anyone can continue with it in the https://gitlab.postmarketos.org/postmarketos/pmaports/tree/feature/more-hildon-packages branch.

CC @NotKit, as you packaged Hildon originally. CC @GrantM11235 as you did some upgrades and clean ups in the past. CC @MerlijnWajer as you're the upstream Hildon maintainer.