IMPORT: STEP colours and IGES trimmed and bounded surfaces

STEP presentation styles colour what they style: a solid in the standard
index colour its RGB is close to, else in the true colour, and a face
with a style of its own (with the edges round it) through the face and
edge colour attributes. IGES trimmed (144) and bounded (143) surfaces
come in as one SURFACE each in the entry's colour, after the solids,
which now come in last first. Faces show a true colour attribute in
that colour.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Cargo.lock

@@ -4382,7 +4382,7 @@ dependencies = [
 [[package]]
 name = "opencadcodec"
 version = "0.6.0"
-source = "git+https://github.com/ramox81/cadcodec.git?rev=6c33e24#6c33e24dc3c72034afec8333f0554541f01cc508"
+source = "git+https://github.com/ramox81/cadcodec.git?rev=58fac2c#58fac2c067cbd1346c08f371aaf92b0807a07f66"
 dependencies = [
  "anyhow",
  "bitflags 2.13.1",