Highlight world map number and letter on bottom and right.

[Raybarg 436]

When hovering mouse over the map, the corresponding row/column letter/number should bold/highlight so it would be so much easier to spot the "S26" youre being told.

Might seem like "Why? You can just look up the column, then carefully look up the row" etc... but when seeing streamers look at the map for coord annotation, its just like with myself, constantly going up/down and left/right to try to desperately keep the mouse going straight up/down and left/right, and it never really does. Ending up wanting to use the world map less because its tedious like that. Slight un-game-breaking thing to highlight the letter/number so we can more easily to see what tile on map we're on or where is the given annotation of a tile on map is.