Add get/set functions in vtkRemoteSession
- the new get method deserializes the object into a state and returns the most up to date state, whereas the
vtkRemoteSession::GetState
only returned a pre-existing state without actually deserializing the object. - deprecates the
vtkRemoteSession::GetState
method. - the new set method allows updating properties on a vtk object either individually or as bulk json.
follow up for !12110 (merged)