Store antenna_by_depth in detector json

[sjoerd-bouma]

The Detector class on initialization has the annoying default argument antenna_by_depth=True even though this results in unusable antenna names for most detectors I have seen in the past 4 years. While we could change this and probably save a lot of inexperienced users some headaches at the cost of technically breaking backwards-compatibility, whether or not antennas are stored as full antenna descriptions or as short strings where the antenna depth suffix should be automatically added is a property of the json, not something that is dynamic at class initialization. I therefore think we should move towards just storing this value inside the detector jsons.

This should be a relatively straightforward change.

[fschlueter]

I absolutely agree. I think it caused me headaches twice (because I forgot it after the first time). Would be great to avoid it in the future!

[cg-laser]

I agree, we can change the default parameter.