Add support for includeSpikes flag in wave data API

[tcj]

Some data points may be omitted without the includeSpikes=true flag, according to the following:

We filter spikes in Peak period that exceed 30s, as these are almost always indications of mooring effects, or other motions not associated with wave motion (eg a unit being picked up by a boat)

Usually a relatively small portion of the time domain data associated with a spectral ensemble is polluted by this type of noise, and we have a more sophisticated on-board time-domain filter in development