Adding lpy (length-pitch-yaw) and saturations modules to plugins folder

Adds lpy.py and saturations.py to plugins folder and readies them to be used by analyze.py. The first module calculates the length, pitch, and yaw (specifically for ITMX) before lockloss, and saves them as a plot in the event directory. The second module does the same for saturating SUS channels before (refined) lockloss time, and also creates and saves a csv of the saturating channels and the times at which they saturate.