Path Insertion Algorithm Improvements

[pizzalemon]

The insertion mode in the frontend path planning page isn't very robust. Under many circumstances, it'll make bad choices, especially after adding jump and home waypoints. To remedy this, I suggest using an A* like approach. Currently, it uses a comparison of the point's projections' onto the lines, which is good in a lot of situations, but isn't perfect. In A*, we use a heuristic to search paths, and here, we could use a heuristic (maybe just distance), which would override the extant algorithm when it's distances are less than the existing algorithm's distances.