Add a toggle to the typing chat overlay

[Zamujasa]

back in ye olde days that was actually a thing and you can still see it if you enable the 'chat' button. if you were typing in the bar to say something it would cut you off with a "--BLURGH" at the end of your message or whatever

you can still see this occasionally from the odd person who uses it, but i don't think it can work quite the same way without a reworking of how speech input is done entirely

(note that this may be a thing on /tg/? code, which uses skin/window controls to create a textbox client-side mostly-lagless textbox, but i don't know how it works beyond the absolute basics)