sanitycheck: Add fixture option for external hardware dependecy

Add a new option as fixture in harness configurations for utilizing
sanitycheck to identify test cases that require external hardware
such as sensor, ble, networking for validation. The config will be
added to yaml files with unique fixture name to identify each hardware
and allow automation to trigger test execution on setup having the
specific fixture enabled. Also, remove the default required for type and
regex configs that is not essential in case of ztest based test cases.

Signed-off-by: Praful Swarnakar <praful.swarnakar@intel.com>