The fix convert all std::string storing a path to wxString (unicode support)
wxString were already used at many place to store paths, but not all.
For internal calculations mixing char strings and wide char strings is a recipe
for bug: any missing conversion between UTF8 and wxString breaks paths.
List of hidden nets stored in project local settings
Hide/Show actions in context menu only for now, will
add them to some more GUI places soon.
Ref https://gitlab.com/kicad/code/kicad/-/issues/1951
Various architecture upgrades to support this.
Creating a BOARD now requires a valid PROJECT, which caused
some (mostly transparent) changes to the Python API internals.
ADDED: Project local settings file
CHANGED: Board design settings are no longer stored in PCB file
CHANGED: Net classes are no longer stored in PCB file
CHANGED: Importing board settings now reads boards, not just projects
Fixes https://gitlab.com/kicad/code/kicad/-/issues/2578
Fixes https://gitlab.com/kicad/code/kicad/-/issues/4070