ftests: Add a test to validate cgx{get,set} systemd options (cgroup v2)

ftests: Add a test to validate cgx{get,set} systemd options (cgroup v2)

Add a test case to validate cgx{get, set} tool's systemd options on
cgroup unified setup mode.

-----------------------------------------------------------------
Test Results:
        Run Date:                          Feb 05 08:15:40
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                                           Time (sec)
        ---------------------------------------------------------
        setup                                                0.00
        070-sudo-systemd_cgxget-cpu-settings-v2.py           3.00
        teardown                                             0.00
        ---------------------------------------------------------
        Total Run Time

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
(cherry picked from commit 418842dcae4285741f1a8ed22a41bfe03d58bdb7)