The functionality is similar to how `doc_classes` are retrieved per module.
The build system will search for custom icons path defined per module via
`get_icons_path()` method in `config.py` or default icons path.
If such paths don't exist, only the editor's own icons will be built.
Most module icons were moved from editor/icons to respective modules.
Thaddeus Crews
MewPurPur
kobewi
Hugo Locurcio
Andrii Doroshenko (Xrayez)