Expose Geometry2D::bresenham_line() to scripting

[timothyqiu]

Bresenham's line algorithm is useful when implementing grid-based drawing tools and doing line-of-sight calculations in roguelike games.

This algorithm is already implemented as Geometry2D::bresenham_line(). I think we can expose it to scripting.

[dalexeev]

• See Expose Geometry2D.bresenham_line() method godot#74714.