Display current firemode on sidebar

[Hirmuolio]

Summary

Interface "Display current firemode on sidebar"

Purpose of change

If you have gun with fireable gunmod (for example underslung shotgun) the sidebar would always show the name of the gun even when you were firing the gunmod.

Describe the solution

Show the active gunmod.

Cycling firemodes on M27 assault rifle with underslung shotgun:
Before:

After:

The name shown on the sidebar is now also a bit more cut down. For example the ammo name doesn't show up in it anymore (it usually doesn't fit in the narrow sidebar anyways). Things like rotten status and frozen status are also not shown anymore, probably they don't matter much in this context. Basically most things that were handled by item::display_name() are left out since that function is not used anymore.

Describe alternatives you've considered

Testing

M27 assault rifle with and without underslung shotgun shows up fine.
A7 laser rifle with and without underslung shotgun shows up fine.

Additional context

weapon.gun_current_mode()->tname() returns the name of the thing (for example "underslung shotgun").
weapon.gun_current_mode().tname() returns firemode of the thing (for example "semi-auto").
That is pretty weird.

[catdach]

Dang, I hoped I had fixed this in #54058. Probably wishful thinking in retrospect. Now I'm not even sure what my little change actually did 😨. Which is really my own fault for not testing it beforehand. If you wouldn't mind, could you look into it for me (and make sure I didn't break anything 🙏 )?

[Hirmuolio]

Your fix maybe fixed the "semi-auto"/"auto" being displayed on the gun depending on the current gunmod mode.