Drive serialization from reflection database

[LPGhatguy]

I'm pretty confident that the reflection database generated in rbx_reflection is pretty solid, and in the cases it isn't we can apply temporary fixups.

In order to make rbx-dom more compatible with Roblox, we should be able to refactor both rbx_xml and rbx_binary to use the reflection database instead of blindly deserializing and serializing every property.

I think I'll start with rbx_binary since it needs attention anyways.