OptionalresolveInvoked for a variable when a user picks the visualizer.
It may return a TreeView that's shown in the Debug Console or
inline in a hover. A visualizer may choose to return undefined from
this function and instead trigger other actions in the UI, such as opening
a custom WebviewView.
Called for each variable when the debug session stops. It should return any visualizations the extension wishes to show to the user.
Note that this is only called when its
whenclause defined under thedebugVisualizerscontribution point in thepackage.jsonevaluates to true.