♻️Typed file loading

Tthis gives us the option to specify what type a file should be loaded
as, avoidng the need to case it and does some automatic checks on the
fitness of the data, while making the process simpler.

If no type is given then the type will be set to std::byte which limit
what operations can be performed on the data.

Source/lighting.cpp

@@ -894,14 +894,14 @@ void MakeLightTable()
 	}
 
 	{
-		auto trn = LoadFileInMem("PlrGFX\\Infra.TRN");
+		auto trn = LoadFileInMem<BYTE>("PlrGFX\\Infra.TRN");
 		for (i = 0; i < 256; i++) {
 			*tbl++ = trn[i];
 		}
 	}
 
 	{
-		auto trn = LoadFileInMem("PlrGFX\\Stone.TRN");
+		auto trn = LoadFileInMem<BYTE>("PlrGFX\\Stone.TRN");
 		for (i = 0; i < 256; i++) {
 			*tbl++ = trn[i];
 		}