HPCC-11573 Deleting LogicalFile/SuperFile Issues

Removed spurious error messages.
Deletion now changes state and icon.
Ignore deleted items in selection.
Removed isSuperfile column.
Added Icon to logical name.

Fixes HPCC-11573

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #6057 from GordonSmith/HPCC-11573

HPCC-11573 Deleting LogicalFile/SuperFile Issues

Reviewed-By: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>