TCAs should label the DEPEND_0 ephemeris parameter, when it is not time

[jbfaden]

Connor is plotting data against L-Shell and then with ephemeris including the time. This leaves the first parameter ambiguous.

We decided that the DEPEND_0 label should be used in this case.

[jbfaden]

Also note that the exponent (-3) in the y-axis title is clipped. See #151

[jbfaden]

I had to touch quite a few codes, as the DEPEND_0 dataset values are generated so are not really a part of this. But I do propagate them now, and the label of DEPEND_0 will be used for non-time-axes.

[jbfaden]