test: refactor unit test suite runner

test: refactor unit test suite runner

Some small changes were made to the unit test suite runner for
readability and to enable reuse of some of the function in a later patch.

On test suite setup skip/fail, the loop to count testcases as
skipped/failed has been moved to another function.
This will allow for recursion in a later patch when nested sub-testsuites
are used.

The unit test suite runner accessed the list of testcases in the suite
structure every time the testcase was used. This is now replaced by a
testcase variable which improves readability.

A macro has been introduced for readability, instead of using open
coded loops.

Rather than keep local variable status counts for testcases,
these are added to the test suite structure.

The summary output now prints the suite name, this will be useful later
when multiple nested sub-testsuites are being run.

Signed-off-by: Ciara Power <ciara.power@intel.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Acked-by: Declan Doherty <declan.doherty@intel.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Acked-by: Akhil Goyal <gakhil@marvell.com>
Tested-by: Ruifeng Wang <ruifeng.wang@arm.com>