Added experimental font family setting on desktop

[chinese-soup]

Font family changing is only visible on non-mobile platforms and tries to use GTK native and macOS native font dialogs, if those are not available, it creates its own "inline" QML FontDialog (which it does for me on Linux and on Windows 10).

I emphasize the word "experimental" mainly because some fonts may be not-fully visible in the text input once the font size is set too high and also the QML FontDialog's theme (the inline one, when native is not available) is currently fugged by our theme (probably), so those are the two (at least) reasons why I'm calling it experimental.

Also changed the SettingsInterface UI alignment a bit in a way that imho looks better: Changed w/ Sans Serif (ignore the HOTLIST being to the left, already fixed in latest commit) Changed w/ Inconsolata

Original:

I have more to come regarding overhauling the settings UI, but I am gonna do that laterrrr(TM)... so here's this for now. No idea what it looks like on mobile, as I don't have means to test it right now (and I am also lazy just like you;))

[chinese-soup]

Windows with Comic Sans MS

macOS with Comic Sans MS

[MartinBriza]

Glorious, thank you!