NSFS | add option to unset supplemental groups using noobaa cli

[nadavMiz]

Explain the changes

1. when setting supplemental groups as empty string (""), unset supplemental groups list for account. this is especially important following NSFS | set supplemental groups dynamically to users groups #8687 as when this value is undefined we will fetch the users groups from the os records
2. continuation of NSFS | NC | add option to set account supplemental groups #8552

Issues: Fixed #8711

Testing Instructions:

automatic test:
run sudo npx jest test_nc_nsfs_account_cli.test.js
manual test:

1. create new user with supplemental groups list defined:
   sudo node src/cmd/manage_nsfs.js account add --name test --uid 808 --gid 808 --supplemental_groups 101,22
2. update account with "" supplemental_groups to unset this value:
   sudo node src/cmd/manage_nsfs.js account update --name test --supplemental_groups ""
3. get status of the account. there should be no record for supplemental_groups:
   sudo node src/cmd/manage_nsfs.js account status --name test

• Doc added/updated
• Tests added

[shirady]

LGTM