ftests: Add a cgroup v2 basic cgget test

ftests: Add a cgroup v2 basic cgget test

Add a test - 003-cgget-basic_cgget_v2.py - that tests
cgget on a cgroup v2 system.

-----------------------------------------------------------------
Test Results:
        Run Date:                          Nov 03 17:49:35
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                                    Time (sec)
        ---------------------------------------------------------
        setup                                         3.76
        003-cgget-basic_cgget_v2.py                   0.70
        teardown                                      0.00
        ---------------------------------------------------------
        Total Run Time                                4.46

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>