Remove some unnecessary files from sandtable app

refs #2259
Updated sandtable catalog description

refs #2259
Remove unnecessary type from sandtable/index.vwf.yaml

refs #2259
Remove unused properties from sandtable/index.vwf.yaml

refs #2259
Remove toolbar child from sandtable/index.vwf.yaml

refs #2259
More refactoring of sandtable app

refs #2259
Fix typo in definition of sandtable clear method and remove comment

refs #2259