Remove elevation handling

For @koem attention as it relates to #2947.

Geocaches do not contain useful elevation information. We used to get it using Google API, but the information was not very useful because our handling of altitude was inconsistent.

Also, the Google elevation API usage limits states that "the Elevation API may only be used in conjunction with displaying results on a Google map; using elevation data without displaying a map for which elevation data was requested is prohibited".

This removes elevation handling completely, except in the settings to avoid getting in the way of the settings rewrite. The elevation related settings should be removed there instead when both works are merged.