Add support for isolating swift storage nets

Add support for isolating swift storage nets

This patch updates the Puppet Swift storage role
so that it supports network isolation. By default
all traffic still flows on the ctlplane network
but if network isolation is enabled then network
traffic will flow over the configured storage_mgmt
network interface.

This patch also fixes a few critical issues with
the swift storage role that prevented it from
working:
 - oac_data for the swift devices was overriding the
   data provided in the swift_devices_and_proxy
   hieradata file.
 - the role was missing declarations to load hieradata
   files for swift_devices_and_proxy and all_nodes
 - The required snmpd settings were not getting set
   correctly in the 'object' hiera data file.

With all of these changes the Swift storage role
works correctly with and without network isolation.

Change-Id: I541abb2604380f603bba91ad88e54783ee450a8f