There is a reason you won't find it, because it's not practical.
Life seems to operate like water, always taking the path of least resistance.
And if you want to be an excellent programmer you will do well to too.
Not trying to discourage you or say it can't be done, just advising that the time it takes to create new scripts that create functionality which an already existing library does can be better used to learn an tailor it to your needs.
For example in the grid based movement you've mentioned above it's very easy to achieve that by setting your grid points 16 pixels apart and assigning an index to them.
When faced with a task bigger than yourself the best approach is to break it up into bite sized pieces or delegate the workload.
Examples
AStar
Quote
“Be like water making its way through cracks. Do not be assertive, but adjust to the object, and you shall find a way around or through it. If nothing within you stays rigid, outward things will disclose themselves.
Empty your mind, be formless. Shapeless, like water. If you put water into a cup, it becomes the cup. You put water into a bottle and it becomes the bottle. You put it in a teapot, it becomes the teapot. Now, water can flow or it can crash. Be water, my friend.”