[REQ] Support ```useTags``` config option for java client code generation

[eyalrin]

Is your feature request related to a problem? Please describe.

I don't want users of my java client library to need to use different API classes to work with my service.

Describe the solution you'd like

Currently in Spring Code Generation there is an option to enable the useTags config option to control whether to generate different API classes for each tag/group or not. I would like this to be supported in the Java Client Generator as well so my customers can use a single API class (this setting should be independent form the Spring Generator since in the server code I still want this separation).

Describe alternatives you've considered

I thought of not using tags at all in my OpenAPI configuration but that make my server code less organized since all paths will need to be implemented in a single class (Since a single API class is generated in that case).

[jekkel]

FYI https://github.com/OpenAPITools/openapi-generator/pull/14794 is gonna cover the feature request albeit in a slightly different way.

[TedGrahamEmporia]

We have the same request. Can you explain how 14794 helps with this?

[jekkel]

With normalizing you're able to adjust all operation's tags to either only the first one (KEEP_ONLY_FIRST_TAG_IN_OPERATION) or to a specific given tag only (SET_TAGS_FOR_ALL_OPERATIONS). Hence the spec can be overridden during code generation and the OP's request of having only a single class for the client can be realized.