Suggest extend over extend-type/extend-protocol when bad :tag metadata would be emitted

[vemv]

From what I learned from https://ask.clojure.org/index.php/10716/is-tag-metadata-that-represents-function-calls-useful?show=10721#c10721 , the c035804 commit is kind of wrong because while the targeted extend-protocol call does work as intended, the :tag metadata it will be emit will be wrong.

OTOH the old behavior of simply failing with :wrong-tag was opaque because it said something was wrong, while it was a functional pattern and no actionable advice was printed.

So, I'm thinking to revert c035804 , and instead when (-> tag first #{'class 'clojure.core/class 'Class/forName 'java.lang.Class/forName}) is detected, the linter message explictitly says:

please use clojure.core/extend instead of %s for dynamically-calculated class names, otherwise the emitted :tag metadata will be wrong.