Add option to generate specialized partition implementation

[Mafii]

No description provided.

[bash]

This looks like a useful addition!

Extension class

I'm a bit unhappy with the separate extension class because it's a new, non-configurable name which lives top level, thus it's totally disconnected from the namespacing of potentially nested unions.

The first is easy to fix (doesn't have to be done now as it is easy to add later in a non-breaking manner). The second is a bit trickier. Given the following example:

public class A
{
	[DiscriminatedUnion(...)]
	public abstract record B 
	{
		// ...
	}
}

[DiscriminatedUnion(...)]
public abstract record B 
{
	// ...
}

If you enable Partition on both top-level and nested B unions, the extension class has to be generated top-level for both (Is that the case currently? If not this needs to be changed. Quoting the compiler error: "Extension methods must be defined in a top level static class").

However, both extension classes are named BEnumerableExtensions and thus conflict.
The easiest solution that I can think of is making the extensions class partial and relying on overloading.

Partitions record

I know we use dedicated structs in Funcky for the partitions. However I'm wondering if that's the right choice here.
Records come with quite a bit of generated members themselves which in this case are double-hidden (once by the record keyword and once since the record itself is generated). Maybe returning a named tuple is better here?

---

(I'm not very active w. Polyadic these days, so feel free to overrule me)

[bash]

lgtm 🎉

Do you have permissions to publish the NuGet package?

[bash]

Oh wait, you forgot to update the docs in the readme :)