Moving Average function reworked to operate better with masked data. The array is extended by extrapolation so that all the data can be returned as averaged. The original mask is reimposed, but not extended, to cover erroneous data areas.
Changes to all functions using the moving_average function to (a) ensure an odd window dimension, (b) remove pad and copy arguments (rarely used, and default when applied) and (c) force the sample rate of Thrust Asymmetry to 1Hz to keep the window dimension consistent (in case different engine data sample rates arise in future).