refine time plot should draw lines indicating the guardian state

the refine time plots include the guardian state, which is useful for seeing what transitions were happening around the time of the lockloss. But it's not obviously from the plots what the exact state was at the time of the lockloss. We should include a horizontal bar, with right axis indicator, of the state at time of lockloss, and we should include a vertical bar that indicates the time that state was entered (both appropriately labelled). maybe in dashed yellow or something.