Replaced node selection functionality and small fixes

Detailed fix list:
- Replaced selection reference with selection key attribute. The
selection reference did not work correctly after refreshing the tree,
also causing endless loops.
- Added application key attribute.
- Select node also across full tree refresh
- Select node will scroll the node into view and expand parent nodes
where necessary.
- Show progress indicator during call to get data microflow
- When updating a node, replace the node class too
- Full tree refresh will remember collapse/expand status of nodes