Adding roundtrip auto update functionality to the CCT Visualization

[cscully-allison]

The CCT visualization now supports auto-updating. If the user places a "?" in front of the input variable name passed as an argument to the visualization it will reload automatically when that variable updates anywhere in the notebook. A second argument is added for the automatic return of selection based and snapshot based queries.

Original functionality is maintained.

Example Syntax:

%cct ?gf ?queries

The data stored in queries is an dictionary comprised of two fields:

{
    tree_state: <string> query describing the current state/shape of the tree,
    selection: <string> query describing the currently selected subtree
}

[slabasan]

@cscully-allison Is this PR ready for review?