Initial Tiled Navmesh Generation (#1689) Goal for this PR is too match current NavMesh functionality, but instead of generating a single large tile, generate multiple smaller tiles instead. This fixes a couple of NavMesh issues, most of them related to nav generation for large maps. Pathing should also improve slightly, since the NavMesh now broken up into smaller polygons. This will be particular noticeable in maps with large empty space and only a few obstacles. The PR does not change the API and should only result in minor behavioral differences, caused by the generated NavMesh being slightly different. https://files.facepunch.com/lolleko/1b0911b1/sbox-dev_w9mTXjsyWd.jpg