Springwolf Cloud Stream - Duplicate key issue if publisher and subscriber have a same topic

[SheheryarAamir]

Describe the bug
Springwolf Cloud Stream - Duplicate key issue if publisher and subscriber have a same topic.

for instance we have below spring configuration for Publish and Subscribe. In this case class CloudStreamFunctionChannelsScanner scan method will throw duplicate exception. as its trying to map topic as a key and in below case topic name is same topic_A. ideally it should merge ChannelItem and setPublish for publisher and setSubscribe for subscriber.

# Binding configuration for publisher
spring.cloud.stream.bindings.createEvent-out-0.destination=topic_A

# Binding configuration for subscriber
spring.cloud.stream.bindings.consumeEvent-in-0.destination=topic_A

Dependencies and versions used
For example, springwolf-cloud-stream-plugin version 0.15.1.

Stack trace and error logs
Duplicate key topic_A (attempted merging values ChannelItem(ref=null, description=null, servers=null, subscribe=Operation(operationId=topic_A_subscribe_createEvent, summary=null, description=Auto-generated description, security=null, tags=null, externalDocs=null, bindings={googlepubsub=ExtendableObject(extensionFields=null)}, traits=null, message=Message(schemaFormat=application/vnd.oai.openapi+json;version=3.0.0, messageId=null, name=org.springframework.messaging.Message, title=Message, description=null, payload=PayloadReference($ref=#/components/schemas/Message), headers=HeaderReference($ref=#/components/schemas/HeadersNotDocumented), bindings={googlepubsub=ExtendableObject(extensionFields=null)})), publish=null, parameters=null, bindings={googlepubsub=ExtendableObject(extensionFields=null)}) and ChannelItem(ref=null, description=null, servers=null, subscribe=null, publish=Operation(operationId=topic_A_publish_consumeEvent, summary=null, description=Auto-generated description, security=null, tags=null, externalDocs=null, bindings={googlepubsub=ExtendableObject(extensionFields=null)}, traits=null, message=Message(schemaFormat=application/vnd.oai.openapi+json;version=3.0.0, messageId=null, name=org.springframework.messaging.Message, title=Message, description=null, payload=PayloadReference($ref=#/components/schemas/Message), headers=HeaderReference($ref=#/components/schemas/HeadersNotDocumented), bindings={googlepubsub=ExtendableObject(extensionFields=null)})), parameters=null, bindings={googlepubsub=ExtendableObject(extensionFields=null)}))

[timonback]

Thank you @SheheryarAamir for the issue and proposed solution. We liked it and merged it right away.

The change will be part of the next release - most likely build today or next Friday.

If you want to try and verify it in your application, use the current SNAPSHOT build as described in our README.md