LDAP: Augment the sdap_opts structure with a data provider pointer In order to be able to use the Data Provider methods from the SDAP code to e.g. invalidate memcache when needed, add a new field to the sdap_options structure with the data_provider structure pointer. Fill the pointer value for all LDAP-based providers. Related: https://pagure.io/SSSD/sssd/issue/2653 Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>

TESTS: Move krb5_try_kdcip to nested group test Avoids duplicate errors during linking. Reviewed-by: Sumit Bose <sbose@redhat.com>

TESTS: Add a common function to set up sdap_id_ctx Reduces code duplication between tests. Reviewed-by: Sumit Bose <sbose@redhat.com>

TESTS: Mock return value of sdap_get_generic_recv Reviewed-by: Pavel Reichl <preichl@redhat.com>

TESTS: Do not require replies from mocked sdap_get_generic_recv to be talloc contexts While it's beneficial for the real implementation of sdap_get_generic_recv() to move memory around, the mocked implementation can just pass around pointer. Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

tests: mock SDAP Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>