HPCC-11778 EclWatch should use NodeGroup instead of ClusterName

For WsDFU related calls, switch to NodeGroup from ClusterName.
Search Results would not open Super Files correctly
SuperFile contents list should not show Cluster
Add "Open in new window" to SuperFile details

Fixes HPCC-11778

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>