v2: Runtime dispatch for ChainViewer CollisionData offset

Chain::CollisionData is at 0x58 (TDB < 71) vs 0x60 (TDB >= 71).
ChainViewer was hardcoded to re2_tdb70 layout (0x58), reading wrong
offset on MHRise/SF6/DD2/RE4 and all TDB71+ games.

Added get_chain_collision_data() dispatcher. All chain->CollisionData
accesses now go through it.

Author: praydog