Copter: Compassmot polls the battery excessively fast

#### Issue details
Copter manually polls the battery read function at 50Hz within the compassmot, this in turn updates the resistance at 50Hz. The filter for this was setup and tuned at a 10Hz call rate, and thus will create different results then would be seen in normal usage. This also logs total consumed with a 5x scalar, but that is at least a safer direction of error.

This should probably be rate limited within the compassmot test, however I didn't want to address this until after the battery failsafe stuff is merged first due to the ever ongoing scope creep.

#### Platform
[ ] All
[ ] AntennaTracker
[ x ] Copter
[ ] Plane
[ ] Rover
[ ] Submarine

Locate the Copter compassmot routine and the battery read function it polls, then inspect how often the call updates resistance and consumed-current logging. Confirm the normal battery filter rate and make the compassmot polling rate match it; done means the test no longer drives battery updates at 50 Hz.

Written by the indexing model from the issue text.