Add lookup table for Hedgewars key IDs instead of generating IDs on the fly
This makes sure the key IDs never change. Previous implementation abused SDL_GetScancodeName to generate the IDs programmatically, which was not reliable and explicitly adviced against in the SDL documentation <https://wiki.libsdl.org/SDL_GetScancodeName#Remarks>.
[patterns]
**.h = native
**.c = native
**.cpp = native
**.lua = native
**.txt = native
**.pas = native
**.inc = native
**.hs = native