Container for all internal pax types
Two important traits are related to this type:
ToFromPaxValue - responsible for converting to and from specific types (u8,
String, Color, etc)
CoercionRules - responsible for coercing a PaxValue to a specific type
(possibly from multiple different variants)
This trait is implemented by all types that has a builtin equivalent
representation (see to_from_impls module) This is NOT responsible for
coercing between types, but returns an err in all cases where the underlying
type is not exactly what is expected