Platforms [Fabric]

- added Platform extension placement system
With wrench in offhand (and not sneaking), clicking a platform (excluding handrails) with a platform of the same type (textures ignored) will place it at the end of the line (preview overlay indicates placement)

- added ramp dropdown placement logic
With wrench in offhand (and not sneaking), placing a ramp on the top of an edge block will instead place it down and forward one block (preview overlay indicates placement)

- fixed Frame climbing and added config for behavior