Add full support for ezTrack

[h-mayorquin]

Not sure if we should migrate this to neurocov but I will write it here so I don't forget.

Ez-track, a software by the Cai lab, can output two types of analysis: Location Tracking and Freeze Analysis.

Location Tracking can be exported as a SpatialSeries with some extra metadata.

The Freeze Analysis data looks like this:

In #4 I opted for following best practices and extracting only the events as they are used in the experiment. A more complete export of the Freze Analysis from ezTrack might decide to save the Motion estimation as a TimeSeries or create a small extension for this.

[alessandratrapani]

see comment: #4 (comment)