Map list should limit content to the visible rectangle

The following discussion from !159 (merged) should be addressed:

• @abcdev started a discussion:

  Looking through the thread linked in issue #120 (closed) . The point that still needs to be addressed is:

  • Filtering of result of the "Show as List" modal by limiting its contents to data within (+ on the edge of) the visible rectangle upon opening

  (Can be solved in follow up issue)