Expand the emoticon library

[cu-kai]

Right now we have a very limited emoticon library, and with full emoji support looking unlikely, could we look to expand our emoticon library to include some more generic icons which may be useful to the game? Things like replacing the ugly cross/tick images, adding country flag emoticons, we could probably use some other generic icons too such as the lightning bolt, bomb emoji, arrows and some signs/symbols.

I propose starting by looking at these: https://openmoji.org

The license seems to match what we're aiming for (CC-BY-SA 4.0) but I Am Not A Lawyer and @illwieckz would probably be the best person to consult on this.

[illwieckz]

Hmm, the license is fine but I do really find some of those emoji ugly 😆️

Anyway, we have this that is still work-in-progress:

• emoji: Add emoji support to rmlui. Unvanquished/Unvanquished#2222

[cu-kai]

Hmm, the license is fine but I do really find some of those emoji ugly laughing

Anyway, we have this that is still work-in-progress:

* [emoji: Add emoji support to rmlui. Unvanquished/Unvanquished#2222](https://github.com/Unvanquished/Unvanquished/pull/2222)

I opened this PR following these comments from @DolceTriade on IRC:

[09:46:28] <+Ishq> I tried emoji support
[09:46:35] <+Ishq> Chances are slim of it happening
[09:47:26] <+Ishq> TL;DR: Emojis are hard and require adding an external dependency in libharfbuzz for full support. Further, require adding ~15 MiB of fonts. Not sure the 2nd is really a deal breaker given the size of our assets, but :shrug:
[09:47:36] <+Ishq> https://github.com/Unvanquished/Unvanquished/pull/2222

[DolceTriade]

Doing some more research, I think it might be feasible to use https://github.com/openSUSE/installation-images/blob/master/bin/strip-font

and reduce the size of the emoji font.

[cu-kai]

I don't think the size of the font is too much of an issue. Game assets can be expected to expand with updates, and 15MiB is hardly a problem these days.