Struct/union name hints

[kubukoz]

It would be great if the Schematic instances for structs generated by smithy4s had a hint for their types' names, or some other way to get that value at any level of the structure.

Currently there's not a (clear?) way to get any of those names, which would be very useful for building tooling / documentation on top of the generated code.

[kubukoz]

Looks like this might be just a matter of a missing .withHints(hints) in val schema everywhere? e.g.

smithy4s/modules/example/src/smithy4s/example/ObjectSize.scala

Lines 7 to 9 in 73d3c9d

	val id: smithy4s.ShapeId = smithy4s.ShapeId("smithy4s.example", "ObjectSize")
	val underlyingSchema : smithy4s.Schema[Int] = int
	val schema : smithy4s.Schema[ObjectSize] = bijection(underlyingSchema, ObjectSize(_), (_ : ObjectSize).value)

@Baccata we talked about this in the context of inputs/outputs only, but it probably applies to everything :) as you've mentioned, this is likely related to #25 - I think hints is now never empty so we should probably render it unconditionally.

[Baccata]

@kubukoz agreed. Additionally, a smoke test related to this would be nice