Enable sorting and use QModelIndex instead of row number to save bookmark selections
After Edit the correct item is selected now.
Moved model initialization code to its own function.

In the few commits before, they were called each time upon refresh.
It was also needed that we tighten requirements of
ISubManager::PopulateModels to make sure models stay consistent.
Try to make bookmark sorts tri-state.

When there is no sorts, they will be sorted by their BID.
Sort order bugfix, now works correctly.