ftests.py: fix test results timing alignment

ftests.py: fix test results timing alignment

The current width length of 35 characters, used as alignment for the
first column in the timing results of ftests.sh.log is not enough and
results in misaligned output. Fix it by assigning the columns format
strings width to the longest filename, calculated just before executing
every testcase. This avoids adjusting the width every time, with newer
testcases. Also, fix the banner separator lines to match the width of
the filename column + 15 (time), dynamically.

without the patch:
```
Timing Results:
        Test                                    Time (sec)
        ---------------------------------------------------------
        setup                                        96.39
        001-cgget-basic_cgget_v1.py                   1.36
        002-cgdelete-recursive_delete.py              4.07
        003-cgget-basic_cgget_v2.py                   0.00
        004-cgsnapshot-basic_snapshot_v1.py           9.41
        005-cgsnapshot-basic_snapshot_v2.py           0.00
        006-cgrules-basic_cgrules_v1.py               0.00
        007-cgrules-basic_cgrules_v2.py               0.00
        008-cgget-multiple_r_flags.py                 1.80
        009-cgget-g_flag_controller_only.py           1.03
        010-cgget-g_flag_controller_and_cgroup.py           1.10
        011-cgget-r_flag_two_cgroups.py               2.34
        012-cgget-multiple_r_flags2.py                3.27
        013-cgget-multiple_g_flags.py                 1.74
        014-cgget-a_flag.py                           1.65
        015-cgget-multiline_r_flag.py                 0.99
        016-cgget-invalid_options.py                  3.30
        017-cgconfig-load_file.py                     1.78
        018-cgconfig-load_dir.py                      2.83
        019-cgconfig-uidgid_dperm_fperm.py            3.40
        020-cgconfig-tasks_perms_owner.py             7.26
        021-cgconfig-invalid_options.py               0.75
        022-cgset-multiple_r_flag.py                  2.21
        023-cgset-copy_from.py                        3.27
        025-cgset-multiple_cgroups.py                 3.14
        026-cgset-multiple_r_multiple_cgroup.py           3.80
        027-cgset-invalid_options.py                  6.42
        029-lssubsys-basic_lssubsys.py                3.60
        030-lssubsys-lssubsys_all.py                  0.72
        031-lscgroup-g_flag.py                        1.81
        032-lscgroup-multiple_g_flags.py              3.20
        033-cgget-no_flags.py                         1.12
        034-cgexec-basic_cgexec.py                    2.49
        teardown                                      0.00
        ---------------------------------------------------------
        Total Run Time                              176.24
PASS ftests.sh (exit status: 0)
```

with the patch:
```
Timing Results:
        Test                                          Time (sec)
        --------------------------------------------------------
        setup                                              95.12
        001-cgget-basic_cgget_v1.py                         1.50
        002-cgdelete-recursive_delete.py                    4.31
        003-cgget-basic_cgget_v2.py                         0.00
        004-cgsnapshot-basic_snapshot_v1.py                 2.68
        005-cgsnapshot-basic_snapshot_v2.py                 0.00
        006-cgrules-basic_cgrules_v1.py                     0.00
        007-cgrules-basic_cgrules_v2.py                     0.00
        008-cgget-multiple_r_flags.py                       1.89
        009-cgget-g_flag_controller_only.py                 1.30
        010-cgget-g_flag_controller_and_cgroup.py           1.20
        011-cgget-r_flag_two_cgroups.py                     6.31
        012-cgget-multiple_r_flags2.py                      3.49
        013-cgget-multiple_g_flags.py                       1.82
        014-cgget-a_flag.py                                 2.36
        015-cgget-multiline_r_flag.py                       1.07
        016-cgget-invalid_options.py                        3.45
        017-cgconfig-load_file.py                           2.58
        018-cgconfig-load_dir.py                            3.08
        019-cgconfig-uidgid_dperm_fperm.py                  3.88
        020-cgconfig-tasks_perms_owner.py                  10.46
        021-cgconfig-invalid_options.py                     0.78
        022-cgset-multiple_r_flag.py                        2.33
        023-cgset-copy_from.py                              3.50
        025-cgset-multiple_cgroups.py                       3.90
        026-cgset-multiple_r_multiple_cgroup.py             4.75
        027-cgset-invalid_options.py                        8.52
        029-lssubsys-basic_lssubsys.py                      1.68
        030-lssubsys-lssubsys_all.py                        0.81
        031-lscgroup-g_flag.py                              2.10
        032-lscgroup-multiple_g_flags.py                    3.49
        033-cgget-no_flags.py                               1.28
        034-cgexec-basic_cgexec.py                          3.21
        teardown                                            0.00
        --------------------------------------------------------
        Total Run Time                                    182.86
PASS ftests.sh (exit status: 0)
```

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Reviewed-by: Dhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
(cherry picked from commit 3e786fc4c024662cc38c8a39868354c55465f487)