Remove obsolete implementation and simplify project structure

src/anyimage/server/models/__init__.py

@@ -0,0 +1,8 @@
+from . import ben2, da3, moge2
+
+
+def geometry_adapter(model_key):
+    return moge2 if model_key.startswith("MOGE2_") else da3
+
+
+__all__ = ("ben2", "da3", "moge2", "geometry_adapter")