Win: Set proper descriptions for tools

This is shown in the file properties and in crash dialogs. Because
of the latter, a short name is better than a description, otherwise
you get dialogs like

  Tool for viewing on-line documentation in Qt help file format
  has stopped working.

Task-number: QTBUG-61970
Change-Id: I9289fe9546a6d9056bbfddb2b6c0bb0ae94684c2
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>