- Arsenal: Migrate (most) text strings to LANGUAGE.

Language-lump-ification

This allows for other mods or patches to either rename or translate the content of the mod. I still have yet to do loadout codes and stuff pertaining to HDUPK though that will come in the future once I figure out a better way to do it.

What does this change?

This makes it so most text strings shown to the player, like pickup messages, tags, menu text and more, are grabbed from a LANGUAGE lump instead to allow for translation to other languages, renaming and more. This also affects all of the weapons zscript files due to needing to change their tag and pickup messages, and usually creating an override for the latter. Any text pertaining to pickup messages is now also stored in Root/LANGUAGE instead of the weapon's zscript file.