SEP-1330: Elicitation Enum Schema Improvements and Standards Compliance

[mikekistler]

Is your feature request related to a problem? Please describe.

Implement support for SEP-1330, which has been accepted for the next version of the MCP spec.

Describe the solution you'd like

Compliance with the next version of the MCP spec within two weeks of its release.

[cliffhall]

PRs implementing 1330 have been made for Typescript and Python SDKs. Happy to collab with maintainers of other SDKs to get this supported across the board.