Fix endianness and padding issues

src/vcd.cpp

@@ -24,11 +24,11 @@ void Vcd::tick()
   for (const auto& [name, entry] : variables)
   {
     stream << "b";
-    for (int i = 0; i < entry.size; i++)
+    for (int i = entry.size - 1; i >= 0; i--)
     {
       uint8_t byte;
       memcpy(&byte, static_cast<const uint8_t*>(entry.ref) + i, 1);
-      stream << std::format("{0:b}", byte);
+      stream << std::format("{:0>8b}", byte);
     }
     stream << " " << name << std::endl;
   }