CP-16259: Probe iSCSI target when IQN is not provided
CP-16259: Probe iSCSI target when IQN is not provided

If an SR create command is missing the target IQN field in the uri,
probe the target and present output formatted in XML

Signed-off-by: Chandrika Srinivasan <51ae5eeda27fe08017d2d63c87755f0707891830@citrix.com>

stefanopanella/xapi-storage-plugins,stefanopanella/xapi-storage-plugins,stefanopanella/xapi-storage-plugins