Improve zoomed refine plots

As mentioned in #161, when a zoomed refined time plot has a threshold crossing outside of the plot window, the channel data outside the window does not get plotted. This is because the code is specifically selecting data that falls within the window. This code plots all the data and chooses xlims based on the refined time and window boundaries.

This generally shouldn't be necessary, as we don't expect good refinement to yield times more than 5 seconds before the unrefined lockloss time, but it's nice to have consistent plots.