Allow filtering for caches with field notes

[+Gamboy]

The map filter allows filtering on caches with personal notes or corrected coordinates but there is no way to filter caches with field notes. This would be helpful to visualize our finds when writing the logs back home for areas with lots of caches where the caches we did not search obscure the map.

 

In the attached picture, for example, this would allow us to see just the exclamation points...