Open single state tree

• Although single state tree does not have any explicit snapshots (views), we create a default snapshot from the root, we also set the new snapshot metadata based on global story metadata (title, description), which is similar to what Molstar does itself.
• Then, we convert the state tree automatically to the multiple kind; we leave the camera empty if no camera node was defined.
• Load state tree into context, from now on, we have unified the behaviour for single and multiplekinds.

Open multiple state tree

• Load state tree into context.
• Selection of the snapshot (view) is possible by different means (using the custom ViewCard UI interface or using the default Molstar UI).
• Based on the user's action, either modify the concrete view in the state tree by overriding it, or push it to the state tree snapshots' list.