KIP-875: First-class offsets support in Kafka Connect

[yeikel]

Issue submitter TODO list

• I've searched for an already existing issues here
• I'm running a supported version of the application which is listed here and the feature is not present there

Describe the feature you're interested in

KIP-875 just debuted on Kafka 3.6 and it would be great to be able to leverage this feature using the UI

Provides first-class admin support for offsets in Kafka Connect. KIP-875 Part 1 added endpoints to get offsets and a new STOPPED state for connectors. The alter offsets and reset offsets endpoints have now been added.

Action	Description
GET /connectors/{connector}/offsets	Retrieve the offsets for a connector; the connector must exist
PATCH /connectors/{connector}/offsets	Alter the offsets for a connector; the connector must exist, and must be in the STOPPED state
DELETE /connectors/{connector}/offsets	Reset the offsets for a connector; the connector must exist, and must be in the STOPPED state
PUT /connectors/{connector}/pause	Pause the connector; the connector must exist

Describe alternatives you've considered

No response

Version you're running

56fa824

Additional context

No response

[acristu]

PUT /connectors/{connector}/pause was supported before KIP-875, the support for stop is needd PUT /connectors/{connector}/stop

KIP-875

[acristu]

if a connector is stopped Kafka Connect page in kafka-ui is broken:

{
    "code": 5000,
    "message": "JSON decoding error: Cannot construct instance of `com.provectus.kafka.ui.connect.model.ConnectorStatusConnector$StateEnum`, problem: Unexpected value 'STOPPED'",
    "timestamp": 1709289310142,
    "requestId": "c6e97ec9-923",
    "fieldsErrors": null,
    "stackTrace": "org.springframework.core.codec.DecodingException: JSON decoding error: Cannot construct instance of `com.provectus.kafka.ui.connect.model.ConnectorStatusConnector$StateEnum`, problem: Unexpected value 'STOPPED'\n\tat org.springframework.http.codec.json.AbstractJackson2Decoder.processException(AbstractJackson2Decoder.java:275)\n\tSuppressed: The stacktrace has been enhanced by Reactor, refer to additional information below: \nError has been observed at the following site(s):\n\t*__checkpoint ⇢ Body from GET http://some-host:8083/connectors/xyzt/status [DefaultClientResponse]\n\t*__checkpoint ⇢ Handler com.provectus.kafka.ui.contr
    .   .   .  .