Do not hide magic DataTable/CSV columns from Feature Info popup

[meh9]

There are some columns in DataTable/CSV's that have special meaning - elevation, time, date, etc, which are used to place a point in 3D space or for generating timeseries control. When matched, the data is then not shown in the Feature Info popup when you click on a feature. However, in most cases we actually want to see the values even if they are used for other purposes. For example, if we hide the elevation data, the user can only get a visualisation of that information back if they tilt their view, but if the user never does that the information has simply been lost to them.

[stevage]

Specifically, VarType.ALT and VarType.TIME should not be suppressed. It's probably still right to hide LON and LAT.

[stevage]

Oh, for some reason I misread this as talking about the variables shown in the "Now Viewing" tab. Probably ok to show everything in the popup.

[stevage]

Wait, I misunderstood this issue again. :) That commit doesn't address it.