Stable, unique names for anonymous OneOf schemas

[Tomboyo]

Given a OneOf schema with anonymous (in-line) schemas in it like the following,

Foo:
  oneOf:
    - type: object
      properties:
        a: ...
    - type: object
      properties:
        b: ...
    

we generate objects named Foo1 and Foo2 in the same package as Foo (per sealed interface rules about packages -v- Java 9 modules). If the order of those two elements changes in a subsequent release of the OAS, then existing code will break: Lily will still generate objects named Foo1 and Foo2, but Foo1 will have property b, not a.

Consider implementing some kind of hash-like function which produces no collisions and is not dependent on element order so that we can create unique names for anonymous schemas that work between releases of the OAS and do not cause name collisions.

[Tomboyo]

Closing as out of date with ADR 0002