[Java][Spring] Ensure class level tags match the operation level tags to stop each operation to appear twice - issue 11570

This fixes https://github.com/OpenAPITools/openapi-generator/issues/11570 by removing the unnecessary tags at the class level. A tag appears in the spec at an operation level - https://swagger.io/docs/specification/grouping-operations-with-tags/

So applying these tags at both controller and operation level is unnecessary. And if you do, the operation appears twice when rendered by a swagger generator, once grouped under the tag for the controller, and once under the tag for the method.

Update: This fixes https://github.com/OpenAPITools/openapi-generator/issues/11570 by ensuring the tag at the class level has the same name as the tag in the operation (specifically, the first tag of the first operation). Previously the class level tag was similar to the operation level tag, but subtly different (e.g. Store vs. store) causing the operation to appear twice in the swagger-ui, once under each tag. Now it is consistent for both controller and operation - store - the operation appears just the once.

@cachescrubber @welshm @MelleD @borsch @Zomzog

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