It should be possible to add controllers for different versions of the same CustomResource

[metacosm]

The change introduced in #626 is too restrictive and will fail if we try to add several controllers for different versions of the same CustomResource.

[csviri]

This is not a requirement, we don't want to support multiple versions of the same CR.
This is the issue it was discussed: #94

[metacosm]

I always forget that 2 versions cannot be served at the same time… so should we keep that change or revert it? Note that the jandex change is needed, though.

[csviri]

I would revert that part so it's not confusing.