[kafka] Implement registry-backed ApiVersions API

[gyang94]

Parent issue

Part of #4185 — Kafka Protocols Compatibility: Basic Produce.

Motivation

Kafka clients need an accurate list of supported API versions before using the server. Capability negotiation should be driven by implemented, registered handlers rather than by a list of placeholder APIs.

Scope

• Implement ApiVersions using the capability registry from [kafka] Add request and transport framework #4264.
• Advertise only registered, public capabilities and their supported version ranges.
• Connect the asynchronous dispatcher to the production Kafka request handler and replace the old switch/stubs.
• Cover supported and unsupported versions, invalid requests, error responses, and capability advertisement.

Acceptance criteria

• ApiVersions returns the server's registered capabilities and version ranges.
• Unsupported versions and malformed requests produce the expected Kafka error responses.
• This stage registers only ApiVersions; Metadata is added by its own follow-up issue.
• Request/response buffer ownership remains correct and relevant Kafka tests and style checks pass.
• The focused implementation is reviewed and merged after its prerequisite.

Dependencies

Depends on #4264.

Out of scope

Metadata, Produce, authentication, schema conversion, Kafka CreateTopics/DeleteTopics, and automatic table creation.

Implementation and review

Implementation PR: #4260.

The PR remains a draft while the framework dependency is pending. Its description includes an incremental comparison for reviewing this stage alone.