gui: some languages not displayed in bitcoin-qt language list

[fanquake]

Ported from: bitcoin/bitcoin#17047.

There are, for now, 4 languages which are not displayed in the windows/linux qt language list. I am not sure about macOS.

These languages are:
Esperanto, Latin, Silesian and Kapampangan.

Side note: My windows machine has the options to switch to Esperanto and Silesian languages, so they do "exist" somewhere in Windows.

Kurdish is also not displayed (correctly?), but I'm not sure if that's only a font issue or not.

QT fetches language names from OS itself, unless otherwise specified. Some info here.
I tried to fix this issue with bitcoin/bitcoin#16808.

On the image: Esperanto name not displayed - (eo).

[GChuf]

bitcoin/bitcoin#16808

[hebasto]

Not sure if this issue should keep open as it seems there is a common opinion (bitcoin/bitcoin#16808 and bitcoin/bitcoin#19001) that this is an upstream Qt bug which is not worth to deal with in our code.