Fix naming of getting vip name method:
method "PluginHelper.full_vip_name" was renamed to "PluginHelper.get_vip_resource_name".
Fix naming of services on nagios: "global-" prefix was added
for plugins with version >=1.0.
Fix checking of haproxy backends state:
removed checks for services,
that don't have haproxy backend.
Fixed disk usage percentage to be consistent
with alerts' criteria.
Temporary disabled checking of openvswitch-agent,
because it is managed by pacemaker.
Removed code duplicity in tests.
Change-Id: If3b77c595fbb5e4348f5f3ebd6e82b445b01062c
Closes-Bug: #1627671
86966e30bd