replace Bytearray with FFI implementation

src/logic/scripting/lua/libs/libbyteutil.cpp

@@ -99,7 +99,7 @@ static int pack(lua::State* L, const char* format, bool usetable) {
         }
         return 1;
     } else {
-        return lua::newuserdata<lua::LuaBytearray>(L, builder.build());
+        return lua::create_bytearray(L, builder.build());
     }
 }
 
@@ -130,8 +130,8 @@ static int count_elements(const char* format) {
 static int l_unpack(lua::State* L) {
     const char* format = lua::require_string(L, 1);
     int count = count_elements(format);
-    auto bytes = lua::require_bytearray(L, 2);
-    ByteReader reader(bytes);
+    auto bytes = lua::bytearray_as_string(L, 2);
+    ByteReader reader(reinterpret_cast<const ubyte*>(bytes.data()), bytes.size());
     bool bigEndian = false;
 
     for (size_t i = 0; format[i]; i++) {