Map midpoint axis lines

[CatTanker]

Introducing a new Layer which makes a vertical and horizontal line which intercepts in the middle of the map

the middle of the map should refer to the visible map area OR the full map, i recommend allowing both, especially for expanding maps

This means mappers can achieve symmetry without having to draw water/walls or other placemarkers manually like

Maybe even allow a function which segments the map into sections (x section x and y sections)

[tomsons26]

To simplify

Draw the yellow lines, visually splitting the map along the width and height centers of the map.
Considering the editor draws the map bounds already should be doable by copying what it does to do that.