Drop serialization_tools dependency

[ModernMAK]

Previously this was used for VStruct and StructX, but with relic.core implementing a c-like serializer inside lazyio, the need for the old toolbox is waning.

Furthermore, it apparently has a few lazy things in it already (BinaryWindow appears to be defined, but it's behaviour is unknown).

Ultimately though, the newer code-base just isn't using it; and the serializer is more readable than the strings used in the struct module.