Cleanup: format all of ./intern, use .clang-format to exclude paths

Directories in intern/ were selectively formatted based on
paths in `tools/utils_maintenance/clang_format_paths.py`.

This had the following problems:

- Editing files inside intern/ would auto-format on save with editors
  setup to auto-format as there was nothing to disable formatting.
- Some directories were missing (by accident it seems).

Resolve by formatting all of `./intern/` exclude except for
`./intern/itasc/` which includes ITASC & KDL versions we might
want to sync with upstream.

intern/quadriflow/quadriflow_capi.cpp

@@ -20,9 +20,7 @@ struct ObjVertex {
   uint32_t n = (uint32_t)-1;
   uint32_t uv = (uint32_t)-1;
 
-  ObjVertex()
-  {
-  }
+  ObjVertex() {}
 
   ObjVertex(uint32_t pi)
   {