Increasing the visibility range of prominent landmarks in the field of view

This is the 3rd video in the field of view series. The previous video can be found here:
https://rumble.com/v3z78gn-taking-into-account-unit-elevation-for-the-field-of-view.html

Commit: adapt the field of view algorithms to use elevation in place of range of sight (2023-12-04 21:37:52)