In volume snapshot command, <volume> is the same
as <snapshot-name> when --volume is not specified,
but <volume> cannot be None, so when <snapshot-name>
is not specified (<snapshot-name> is None), a NoneType
error appears.
So make <snapshot-name> no longer optional, it should
be always present.

Change-Id: I3d9f10753a8ef601e70816421c160598e2cc811f
Closes-bug: #1659894

Supporting "--no-property" option will apply user a convenient
way to clean all properties of volume snapshot in a short command,
and this kind of behavior is the recommended way to devref.
The patch adds "--no-property" option in "volume snapshot set" command,
and update related test cases and devref document.

Change-Id: I5f10cc2b5814553699920c4343995b2e11416e4e
Implements: blueprint allow-overwrite-set-options

Add "--project" and "--project-domain" option to volume v2's
"volume snapshot list" command, it will filter list result by different project.

Change-Id: I7dccd6d8d9f1889fa9cb0c2d04a42d77975c645b

Add "--remote-source" option to "volume snapshot create" command
to support creating snapshot from an existing remote snapshot in
volume v2 (v2 only), also add the doc, unit tests and release note.

Change-Id: I9e5fad4f0db5b44d528eb6b930edbc816e392c3a
Implements: bp cinder-command-support
Closes-Bug: #1618676
Co-Authored-By: Sheel Rana <ranasheel2000@gmail.com>

Add '--force' option to 'volume snapshot delete' command in
volume v2 (v2 only) to allow delete in state other than error
or available.

Change-Id: Ie8991e9a630d7c7e9ac6c6870aed787bbcebacf2
Closes-Bug: #1597195

Add "--name", "--status" and "--volume" options
to "volume snapshot list" command for filtering results.

Change-Id: I72db1abce7701f31598deec34801a4d1f5713870
Closes-Bug:#1645252

1.change the command name ``snapshot create/delete/list/
show/set/unset`` to ``volume snapshot create/delete/list/
show/set/unset``.

2.change the optional parameter "--name <name>" to a
positional parameter "<snapshot-name>"; Change the
positional parameter "<volume>" to a optional
parameter "--volume <volume>"

Change-Id: If03276ecdf6f0d96893d5ecf91c2aaa64929cff3
Implements: bp backup-snapshot-renamed-for-volume-resource
Co-Authored-By: Sheel Rana <ranasheel2000@gmail.com>

Support multi REST API calls error handling for
"snapshot set" command follow the rule in
doc/source/command-errors.rst. Also add a unit
test for testing the error handling

Change-Id: I0c6214271bc54a25b051c0a62438c3344c8b51d7