* [Schema] Stop rejecting elicitation schemas the specification allows
The specification makes `title` optional on every elicitation schema
definition. AbstractSchemaDefinition required it, so a client reading a
conformant server's elicitation/create refused the request - and a server
building one could not omit it either.
`title` is now nullable on all seven definitions, omitted from the
serialized form when absent, and rejected only when present and not a
string.
* Fix stale title docblocks; allow omitting title where safe
* Give Number's title param a default too
* Apply suggestions from code review
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
- Add ElicitAction enum (accept/decline/cancel)
- Add schema definitions for elicitation fields (string, number, boolean, enum)
- Add ElicitationSchema wrapper for requestedSchema
- Add ElicitRequest and ElicitResult for elicitation/create method
- Update ClientCapabilities to support elicitation capability
- Add elicit() method to ClientGateway
- Store client capabilities in session during initialization
- Add comprehensive unit tests
- Add elicitation example server with book_restaurant, confirm_action, and collect_feedback tools
