Generator-jhipster: v7 - remove serviceClass generation

[Tcharl]

Overview of the feature request

As of today, we have serviceClass and serviceImpl generation available.
serviceImpl looks to be the best option, which is compliant with modulith, bounded context, side by side and friends.
Also, it's not a big overhead for the end user and can even be simplified

@MyEntity
public interface MyEntityService extends CrudService<MyEntity> {}

Motivation for or Use Case

Simplifying the generator.
generators more easy to maintain

Related issues or PR

10958

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[pascalgrimaud]

We don't have any issue since years about this. No issue, no maintenance to do on this part.
Both (serviceClass and serviceImpl) works very well, I'd prefer to keep both options, so the end user will have the choice.

[Tcharl]

It's always better to have the choice written :-).

Thank you @pascalgrimaud @murdos