Add wavefront planner

[veds12]

https://www.youtube.com/watch?v=Ls8EBoG_SEQ&t=1694s

This lecture is a good starting point to understand apf planning algorithms. A unique requirement in wavefront planner is that you need to represent the planning area in the form of a grid world. Asking the user for the coordinates of the points enclosing the grid environment(for eg. the coordinates of end points in case of a polygonal grid world) would be the preferable way to go about this. The dimension of each cell in the grid depends upon the intended resolution