[KIP-482]: Update CreateTopics API

[PratRanj07]

Update CreateTopics API to v5(First flexible version)
Now the CreateTopics response returns topic configs too

[confluent-cla-assistant]

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[Copilot]

Pull Request Overview

This PR updates the CreateTopics API to version 5 (the first flexible version) per KIP-482, enabling the CreateTopics response to return topic configuration data in addition to basic topic creation results.

• Updates API version support from v4 to v5 with flexible message format
• Adds new fields to topic result structure for partition count, replication factor, and configuration entries
• Implements parsing logic for the enhanced response format with topic configuration data

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/rdkafka_request.h	Adds function declaration for reading topic config error codes
src/rdkafka_request.c	Implements topic config error code parsing and updates request format to v5 with flexible arrays and tags
src/rdkafka_aux.h	Extends topic result structure with new fields for partition count, replication factor, and configs
src/rdkafka_aux.c	Implements getter functions for new topic result fields and updates constructor/destructor
src/rdkafka_admin.h	Adds declaration for ConfigEntry constructor function
src/rdkafka_admin.c	Implements response parsing for v5 format including config entries and updates ConfigEntry visibility
src/rdkafka.h	Adds public API functions for accessing new topic result data
tests/test.c	Adds test assertions for verifying partition count and replication factor in topic results

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[Copilot]

The condition checks if *cntp is zero before reading the list count. This logic is backwards - it should check if cntp is NULL to avoid dereferencing a null pointer, then set *cntp to the list count.

Suggested change

	if (!*cntp)
	return NULL;
	*cntp = rd_list_cnt(&topicres->configs);
	size_t cnt = rd_list_cnt(&topicres->configs);
	if (cntp)
	*cntp = cnt;
	if (cnt == 0)
	return NULL;

[Copilot]

The variable log_decode_errors is declared but never used in this function. It should be removed or used in error handling.

Suggested change

const int log_decode_errors = LOG_ERR;