inspector: graph: highlight all buggy outputs
inspector: graph: fix navigating to system right after expanding parent

Invoke "navigateToItem" method using a queued connection to allow
time for layout processing.
inspector: rename a misnamed variable
inspector: DebugWidget: remove unused method declaration
inspector: prototype menus, toolbars
inspector: qml: improve an item id for clarification
inspector: implement (re)opening systems at runtime