Feature Request: All Ballistics keybind

Blasters and missiles each have a dedicated fire-all button (Fire all blasters is RMB, fight me). I'd like the same for Ballistics so that the later double ballistics builds don't need to rely on weapon groups.

Not hugely important.

The issue names no files or tests. Start by locating the existing dedicated fire-all blaster and missile keybinds, then trace how their actions reach weapon firing; done means Ballistics has an equivalent fire-all action that works for double-ballistics builds without weapon groups.

Written by the indexing model from the issue text.