to run test execute:
   test-runner.sh --skip-cover --skip-small-tests --preset pgsql_mnesia --db pgsql -- dynamic_domains_pm:can_authenticate

…se_domain_core_SUITE:init_per_testcase/2

esuring dialyzer is not complaning:
   ./rebar3 dialyzer

introducing the new callback supported_features/0:
  * for now there is the only one optional feature - dynamic_domains.
  * currently only ejabberd_auth_dummy supports dynamic_domains feature.
  * all other auth modules must be rechecked and adopted in order to
    support dynamic_domains feature.
  * the following things must be done per auth module:
       - recheck that ejabberd_auth set_opts and get_opt interfaces are
         used with host type, not domain name.
       - recheck that mongoose_scram interfaces are used with host type,
         not domain name.
       - recheck that ejabberd_config get_local_option interfaces are
         used with host type, not domain name.
       - create proper tests to ensure that auth module works correctly
         with dynamic domains.

commit verified with the following commands:
   test-runner.sh --skip-cover --skip-small-tests --preset pgsql_mnesia --db pgsql -- dynamic_domains_pm:can_authenticate
   ./rebar3 dialyzer

verified with commands:
   tools/setup-redis.sh
   ./rebar3 ct

tested with this command:
   ./rebar3 ct --suite auth_dummy_SUITE --case supports_dynamic_domains

tested with command:
   ./rebar3 ct --suite config_parser_SUITE --group host_types_group

it causes execution of meck:unload in parallel which results in spontaneous failuers.
tested with:
   ./rebar3 ct --suite config_parser_SUITE

…iour