Show 'real' map size to players in world map

[TheRealBecks]

TL;DR

When opening the world map the player shall get the option to render a border around the 'real' and not yet revealed map chunks

What ?

There shall be a button in the world map so a border around the 'real' and not yet revealed map chunks can be rendered. So the player will get an idea of the real map size. He will understand that the map is bigger than the chunks that have been revealed by the radars.
Real map size in my savegame:

real_map_size.png (153.64 KiB) Viewed 655 times

The chunks have been created by pollution:

pollution.png (268.42 KiB) Viewed 655 times

Why ?

In lategames it's unclear why the performance (UPS) is bad and why the savegame file is such high. It's sometimes happening because of the pollution spreading out and new chunks get generated. Also there are hidden biters and biter nests and the performance drops massively. With that new map option the player can see if the pollution spreads to massively out.