Revert "Add lookForNewBlocks so that we look for new blocks not bridge locations"

This reverts commit 1e74e96a78b03f6f22391c282ff36777748b1e5c.
Revert "And I need GridMotionGraph.nodes_map for my change"

This reverts commit bab8fdf4c443c12777bbe896840e9637cfd4cb65.