Initial extraction of the empty main window shell.

Contains some crude buildsystem scaffolding and just shows an empty window,
need an replacement for the ToolModel next.
Add client side tool model and very crude integration of the object tree.

This is full of hacks, but it shows a path forward.
Split out model handling from the property widget.

This still needs to be completed with everything else that is independent
of the UI and needs to run inside the probe.
Crude integration of the property controller.

For the object inspector we now see the property views in the client as
well, and can edit them.
QSFPM triggers this assert by calling index() during begin/endInsertRows.

Still needs to be investigated.
Move some of the signal monitoring code here.
Test integration of NetworkObject for performing method calls.
Properly handle proxy models when synchronizing selection models.

Now hierarchies and client-side sorting do no longer mess up the selection.
Listen to selection rather than current changes.

Only selections are reliably mapped between client and server.