Consider Implementing `IParseable` in .NET 6

[RehanSaeed]

Describe the feature

See https://devblogs.microsoft.com/dotnet/preview-features-in-net-6-generic-math/#static-abstracts-in-interfaces

public interface IParseable<TSelf>
    where TSelf : IParseable<TSelf>
{
    static abstract TSelf Parse(string s, IFormatProvider? provider);

    static abstract bool TryParse([NotNullWhen(true)] string? s, IFormatProvider? provider, out TSelf result);
}

[Turnerj]

Interesting - you thinking have this on Thing or maybe each of our derived types implements it? Should mostly be able to pass it off to the SchemaSerializer class.

[RehanSaeed]

I was thinking it would be nice to have it on Thing as just a convenience method.

[Turnerj]

If we can't make use of #310 (source generators from S.T.J), we could even use these methods to output custom serialization for a type from our own source generator. That is to say, we'd generate it ourselves when we generate the model.