## Summary of Changes
While experimenting on self-intersecting polyhedral surfaces, I met two
bugs:
* `edge_min_size` was not enough taken into account in
`Protect_edges_sizing_field`,
* `edge_distance` was missing the information of which `curve_id` the
edge belongs to (available using internal code)
causing crashes.
## Release Management
* Affected package(s): Mesh_3
* License and copyright ownership: unchanged
## Summary of Changes
This PR removes outdated conditional blocks that check for specific Qt
versions since CGAL now uses Qt6 exclusively.
## Release Management
* Issue(s) solved (if any): #8381
## Summary of Changes
Versions >= 9 of VTK trigger the following CMake warning using CGAL's
CMakeLists
```
CMake Deprecation Warning at C:/dev/VTK-9.2.2/build/lib/cmake/vtk-9.2/vtk-use-file-deprecated.cmake:1 (message):
The `VTK_USE_FILE` is no longer used starting with 8.90.
Call Stack (most recent call first):
CMakeLists.txt:32 (include)
```
I suggest this modification of the CMakeLists of Mesh_3 examples, that
also requires moving to VTK 9 (9.0 was released in 2020).
If this modification and new requirement are validated, I can apply the
change everywhere.
## Release Management
* Affected package(s): Mesh_3 for now
* License and copyright ownership: unchanged
## Summary of Changes
Switching from `std::pair<Property_map<T>, bool>` to `std::optional` in
`Property_container::get<T>`
Introducing `Pair_optional_adaptor` for backward compatibility which
extends `std::optional<T>` to interface of `std::pair`
using `Pair_optional_adaptor` for `Surface_mesh` and `Point_set_3`
## Release Management
* Affected package(s): Point_set_3, Surface_mesh, STL_Extension
Laurent Rineau
Andreas Fabri
albert-github
Sebastien Loriot
Jane Tournois
Sven Oesau
Jane Tournois