CLOUDSTACK-3905 [VMWARE]Can not add Standard/DVSwitch when Nexus global config is set to true

Make VSM specific input paramters optional while adding VMware cluster where no traffic chosen to use Nexus 1000v dvSwitch when cloud level vSwitch is Nexus 1000v.

Signed-off-by: Sateesh Chodapuneedi <sateesh@apache.org>
CLOUDSTACK-4269: UI > account page > hide Setting tab for regular-user/domain-admin since they don't have access to listConfigurations API.