core: Allow changing CSV params in vdc_options

In case vdc_option contain several values seperated by commas,
this patch will give a nice stored procedure to remove a value
from such a param.

Change-Id: Ic25172a8b44e2f0aec81fe48808803c31b5f327b
Signed-off-by: lzelkha@redhat.com <lzelkha@redhat.com>