Design properties: project, author and licence in the design, its exports and inspect_design (#1015) (#1189)

A design carries metadata (format 21): project, part number, revision, author, organization, description and license, plus other tools' data under reverse-DNS keys, kept as written. Edited in the Design Properties window (Document Settings), set by document.metadata.set, reported by inspect_design, and written into STEP, IGES and 3MF where the format has a place for them. Translated, with tests.

crates/ui-egui/src/documents.rs

@@ -87,6 +87,7 @@ fn swap_in(app: &mut SolveApp, slot: DocSlot) -> DocSlot {
     crate::dim_view::cancel();
     app.tool = None;
     app.params = None;
+    app.design_properties = None;
     app.cancel_view_animation();
     app.viewport.orbit_snap = None;
     app.viewport.orbit_free = None;