Align MethodInfo equality check with engine

[Naros]

Fixes the MethodInfo equality operator== check to use the name like in the engine.

I came across this because I was using some similar code to the engine that does:

if (!(info == MethodInfo())) {
  /* do stuff */
}

And I could not understand why a full MethodInfo would not trigger the if-block. 😭

[Naros]

@dsnopek @Ivorforce, this is at least the second or third time I've come across inconsistencies between these structs (MethodInfo / PropertyInfo), since they're defined in both the engine and the godot-cpp side. Is there any chance we can develop some sort of check that prevents this from happening, where the engine and godot-cpp get out of sync?