Log Browser: map display zoom level reset when any checkboxes are checked/unchecked

It would be nice if the map view's zoom level was left as-is (e.g. not reset to the default zoom level) when some of the checkboxes are checked or unchecked. The graph view is not reset so I don't think the map view should be reset either.

The checkboxes that shouldn't affect the map zoom level are "Mode", "Errors", "Msg" and "Events".

Similarly it would be nice if the zoom level wasn't changed when new items are added to the graph. For example, if I check the "ATT.Roll" value in a copter log, the map zoom level is immediate returned to the default.. I'm just plotting a new piece of data, I don't want the map to reset each time. unchecking a data item doesn't seem to cause a map zoom level reset by the way (which is good).

Start at the Log Browser's map zoom handling and the checkbox and new-data paths described in the issue. Trace why changing Mode, Errors, Msg, Events, or plotted values changes the map zoom, and verify that those actions preserve the current zoom while the graph behavior remains unchanged.

Written by the indexing model from the issue text.