Feature: Reload languages with a keybind

[ChloeDawn]

When experimenting with and tweaking localization for things such as tooltips, messages and names, it is pretty frustrating that the only way to update it in-game is to trigger an entire resource reload that can take 10+ seconds to run, with an obnoxious splash screen. A keybind to reload only languages would be super useful, and reloading languages alone is a very fast operation, so there would be no need to "take a break" to a splashscreen or anything. The keybind could possibly be an F3 function such as F3+L.