GLM plotting does not filter by time bounds

[wx4stg]

I'm not really sure what the default behaviour "should" be here, but when plotting GLM events on an already existing xlma BlankPlot, the GLM events are plotted on the plan and cross sectional axes regardless of whether or not the events fall in the timeframe specified by the BlankPlot's tlim

[deeplycloudy]

I believe the way I handled this in the draft implementation was to have a filtering function that was called as part of a custom subclass in the notebook. So those subsetting functions exist and can get rolled into an if has_glm: part of the default interactive class. Maybe blank_plot can call the same subsetting logic for the static plot.