coraid: fix snapshot deletion

coraid: fix snapshot deletion

Currently, a request to ESM API for a snapshot deletion looks this way:

{'addr': 'cms',
 'data': {
    'repoName': repository_name,
    'lvName': snapshot_name},
 'op': 'orchStrLunMods',
 'args': 'delClSnap'}

This is correct, however, some versions of the ESM API have a bug that
prevents it from validation this valid request and it fails with:

Must define the new LV name to be assigned to the clone/clSnap.

As a workaround for this bug, provide an 'newLvName' property with a
'noop' value to make the validation pass even on buggy versions.

Fixes bug #1365417

Change-Id: I3fd7f3c6a64cac992735b098368b52b9ab21d85c