feat(cursor): add crosshair options

Add persistent cursor sizing, pick aperture, color, pointer mode, isometric drafting planes, and SNAPANG-aligned grid behavior.\n\nRefs #413

src/ui/window/mod.rs

@@ -3,6 +3,7 @@ pub mod block_palette;
 pub mod layout_manager;
 pub mod layer_state_manager;
 pub mod drawing_units;
+pub mod drafting_settings;
 pub mod layer_translator;
 pub mod plot;
 pub mod print_all;