Kafka Connector documentation improvements

[mesellings]

Feedback on improvements for the Kafka Connector docs: https://camunda.slack.com/archives/C026U8GBNSW/p1734353340950709

Description

Clarify that in some circumstances, modifying some configurations in the kafka connector element model, can lead to unexpected behaviours and that it’s safer to delete the element and create a new one.
Explain how to handle cases where the scenario in this red box happens and especially when:
It just happens. Ok, we know that there is a danger red box, but a fixing strategy should be documented
A customer is updating the cluster from a version where the “Consume unmatched events checkbox” was not present.

Actions

Add this to a dedicated page on how to work with inbound Connectors and their lifecycle.

[mesellings]

FYI @garima-camunda @sbuettner