Handle type aliases in Python 3.12+ correctly.

[lojack5]

I was going through and updating internal typing used in the library, and ran across this issue:

type MyType = uint8

class Test(Structured):
  a: MyType

Here a won't be detected as a serializable type. The same thing doesn't happen with the older syntax of MyType: TypeAlias = uint8, as it is actually assigned the value of uint8. With the new syntax however, a TypeAlias object is created instead (technically, a typing.TypeAliasType object).

So we'll need to handle this correctly. Some relevant information stored on the TypAliasType object that will be needed:

• __value__ holds the assigned value of the TypeAlias, this is what will be needed to be examined for serializability checks
• __name__ holds the name of the TypeAlias, probably not needed
• __type_params__ holds type parameters (typevars, typevartuples) for generic TypeAlias's.