Change some headers for admin cli ls

[andrewjstone]

Attached To -> Attached To VM
Created By -> Created By VM

Tested with make all and CI

Fixes #434

[kerneltime]

LGTM

[pdhamdhere]

LGTM.

[msterin]

LGTM. This one was easy :-)

P.S. It does show

Running unit tests in /tmp/vmdk_ops_unittest3288/vsan_policy_test.py...
...ERROR:root:Failed to remove test_policy policy file
Traceback (most recent call last):
  File "/tmp/vmdk_ops_unittest3288/vsan_policy.py", line 90, in delete
    os.remove(policy_path(name))
OSError: [Errno 2] No such file or directory: '/vmfs/volumes/vsan:5204bc8bc03e1c20-5a4696067b772017/dockvols/policies/test_policy

in the log - is it false positive ?

[andrewjstone]

As discussed with Mark the other day, this is just a log message during a negative test, which is why CI still passes. Will work to somehow disable or annotate it.