Lift certain incorrect assumptions about the order of vertices in an OBJ file when processing vertex colors, which could lead to missing or randomly permuted colors. Replaces the list-of-blocks representation, attuned to assumptions that the verts in an object form a contiguous subrange, with a flat array better suited for random-access. Co-authored-by: scurest <scurest@users.noreply.github.com> Pull Request: https://projects.blender.org/blender/blender/pulls/126065