Promote logics in auth::authentication::Authenticate to a public api, which unfortunately cannot be the same due to the inconsistent naming, hence we have to create a new alias
Rationale: - the proc provides some value to the user by choosing the right contract implementation depending on the authority - we found occurrences in other packages downstream, and as internally this proc is calling only public api, one could just duplicate the whole thing and be compliant with our standards, which is not an improvement IMO - the proc was already tested and documented
fixed bug: exception in test case auth_use_email_for_login_p caused test to terminate
By adding an "ad_try", we can see that the intention to create a user with no username failed. Probably this was working at some time, not sure, if it still should.
This is could be a general problem with "aa_run_with_teardown" to terminate too early in such cases.