Multiple documents for configuring Kafka Inbound

Description

In our documentation we have 2 configuration documents[1][2] for Kafka Inbound endpoint. One under Connectors -> Kafka Inbound and Inbound endpoints -> Kafka. In [1], we have mentioned about setting the protocol as Kafka, however in the example pointed in that doc, it mention to use the Inbound connector from the store and configure it in the same way as [2]. Furthermore, the Kafka Inbound implementation in MI[3] related to [1] is comparatively old. Hence IMO, it's better to deprecate it and move forward with Kafka Inbound connector[2]

[1] - https://mi.docs.wso2.com/en/latest/reference/synapse-properties/inbound-endpoints/polling-inbound-endpoints/kafka-inbound-endpoint-properties/

[2] - https://mi.docs.wso2.com/en/latest/reference/connectors/kafka-connector/kafka-inbound-endpoint-config/

[3] - https://github.com/wso2/micro-integrator/blob/master/components/mediation/inbound-endpoints/org.wso2.micro.integrator.inbound.endpoint/src/main/java/org/wso2/carbon/inbound/endpoint/inboundfactory/InboundRequestProcessorFactoryImpl.java#L83

Compare the two documented entry points: the Kafka inbound endpoint properties page and the Kafka connector inbound endpoint configuration page. Review the linked InboundRequestProcessorFactoryImpl.java implementation for context, then update the documentation so the older Kafka inbound endpoint is deprecated and users are directed to the Kafka Inbound connector configuration.