Add topic/partition assignment data to consumer group members

[shouples]

The ConsumerAssignmentData client model already provides topic_name and partition_id per consumer, but neither the Consumer model nor any loader utility currently fetches or stores this data.

vscode/src/clients/kafkaRest/models/ConsumerAssignmentData.ts

Lines 36 to 91 in 5fcff5b

	export interface ConsumerAssignmentData {
	/**
	*
	* @type {string}
	* @memberof ConsumerAssignmentData
	*/
	kind: string;
	/**
	*
	* @type {ResourceMetadata}
	* @memberof ConsumerAssignmentData
	*/
	metadata: ResourceMetadata;
	/**
	*
	* @type {string}
	* @memberof ConsumerAssignmentData
	*/
	cluster_id: string;
	/**
	*
	* @type {string}
	* @memberof ConsumerAssignmentData
	*/
	consumer_group_id: string;
	/**
	*
	* @type {string}
	* @memberof ConsumerAssignmentData
	*/
	consumer_id: string;
	/**
	*
	* @type {string}
	* @memberof ConsumerAssignmentData
	*/
	topic_name: string;
	/**
	*
	* @type {number}
	* @memberof ConsumerAssignmentData
	*/
	partition_id: number;
	/**
	*
	* @type {Relationship}
	* @memberof ConsumerAssignmentData
	*/
	partition: Relationship;
	/**
	*
	* @type {Relationship}
	* @memberof ConsumerAssignmentData
	*/
	lag: Relationship;
	}

Will need:

• A loader function to fetch assignments per consumer (similar to fetchConsumerGroupMembers in Add base loader method for listing consumer groups #3229)
• An assignments property on the Consumer model (Add basic ConsumerGroup and Consumer models #3299)

We'll need to figure out when to load this data, since it could be helpful when seeing the topics for a given Kafka cluster, but only loading it in certain scenarios (e.g. expanding a single ConsumerGroup) may require too much manual clicking by the user.