unified by-contract-ID/createAnd exercise interface, deprecate createAndExercise methods

[S11001001]

Design from #13668 (comment) . For this part:

• declare codegen.Exercises<Cmd> with makeExerciseCmd
• implement makeExerciseCmd in codegen.ContractId which now implements Exercises<ExerciseCommand>
• define codegen.CreateAnd<...> implements Exercises<CreateAndExerciseCommand>
• define createAnd() on templates
• move exercise methods from ContractId to separate generated interface with default methods in terms of makeExerciseCmd
• define codegen.ByKey<...> implements Exercises<ExerciseByKeyCommand>
• define static byKey(...) in terms of ByKey and Exercises
• propagate extra TemplateId in the toInterface cases for create-and, by-key
• emit deprecation annotation and maybe Javadoc for all existing createAndExercise and by-key methods