Request for map markers to designate landmarks and obstacles

I recently returned from the Philippines where I had the opportunity use MP in various settings. I compiled a wish list of items that would improve the usability of MP and will post them all separately for tracking.
1. Map Markers -
When I arrive at a new site I need to determine where the landing runway will be to set up the autoland. To be certain that the map matches the site, I always walk the runways. I would like to have the ability to place labeled markers on the map for reference. This will also help me to quickly set up a new autoland if the wind direction switches. Often there are obstacles that I would like to avoid that aren't easy to see on the map. It would assist in the pilot's situational awareness to be able to identify these objects.

The issue names no files, tests, or entry points. Start by locating Mission Planner’s map interaction code and determine how map objects are currently represented. Done means users can place labeled markers for landmarks and obstacles and see them reliably on the map.

Written by the indexing model from the issue text.