Implement Make Biconnected Planar and Make Maximal Planar Algorithms for pgRouting

This project implements pgr_makeBiconnectedPlanar and pgr_makeMaximalPlanar as new pgRouting SQL functions, completing the planar graph preparation. Together they unlock downstream Boost layout algorithms currently inaccessible to pgRouting users. Stretch goal: pgr_findOddCycle. Estimated 350 hours.