Delete define-class indirection

[aadcg]

nclasses is a library maintained by @atlas-engineer/atlas so it's odd that define a macro on top of nclasses:define-class.

We don't need *automatic-types-p* set to t. *accessor-name-package* could easily be set to :slot-name by default. The default value of *predicate-name-transformer* is a good default and we don't to rely on nclasses:always-dashed-predicate-name-transformer.

[jmercouris]

I think this decision was made pre-fork. I'm not exactly sure the history behind it, there was however some reasoning.

[aadcg]

@jmercouris that doesn't seem correct since both *automatic-types-p* and *predicate-name-transformer* were for sure included by (past) members of the Atlas team.