[KIP-482]: Update OffsetForLeaderEpoch API (v2 -> v4)

[Ankith-Confluent]

Upgrades OffsetForLeaderEpoch protocol to v4, adding ReplicaId field (v3) and flexible protocol format (v4).

v3 changes

Added ReplicaId field to improve permission model (KIP-320):

• -1 for consumer requests (requires TOPIC-level Describe permission)
• broker_id for follower replica requests

v4 changes

Adopts flexible protocol format with compact arrays, compact strings, and tagged fields for future extensibility.

[confluent-cla-assistant]

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[Copilot]

Pull request overview

This PR upgrades the OffsetForLeaderEpoch protocol from version 2 to version 4, implementing KIP-482 changes. Version 3 adds the ReplicaId field to improve the permission model (KIP-320), while version 4 adopts the flexible protocol format with compact arrays and tagged fields.

Key changes:

• Added ReplicaId parameter (-1 for consumer requests) to the OffsetForLeaderEpoch request API
• Implemented flexible protocol format support (v4) with tagged field handling in request and response paths
• Updated mock handler to support versions 2-4 with proper tag skipping and writing

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/rdkafka_request.h	Added replica_id parameter to OffsetForLeaderEpochRequest function signature
src/rdkafka_request.c	Implemented v3 (ReplicaId field) and v4 (flexible format with tags) protocol support in request/response handlers
src/rdkafka_offset.c	Updated offset validation to pass ReplicaId=-1 for consumer requests
src/rdkafka_mock_handlers.c	Enhanced mock handler to support v3-v4 protocol with ReplicaId reading and tag handling at all nesting levels

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