Give solid.move the copy half of its Move/Copy label (#498)

solid.move takes copy: true to keep the source bodies and transform a new copy of each, with a Create Copy box in the Move dialog. Designs without it save and load exactly as before.

crates/ui-egui/src/dialogs_move.rs

@@ -226,6 +226,9 @@ pub fn params(app: &SolveApp, d: &Dialog) -> Result<Value, String> {
             p["translate"] = num(at - from);
         }
     }
+    if d.extra.get("copy").and_then(Value::as_bool).unwrap_or(false) {
+        p["copy"] = json!(true);
+    }
     Ok(p)
 }
 
@@ -285,7 +288,7 @@ pub fn drag(app: &SolveApp, d: &mut Dialog, g: Drag) {
 
 /// The dialog for editing a move: Free Move with its translation and, about a world axis
 /// through the origin, its angle (another axis is kept as it is).
-pub fn for_feature(d: &mut Dialog, bodies: &[String], translate: &[String; 3], axis: Option<Vec3>, angle: Option<&String>) {
+pub fn for_feature(d: &mut Dialog, bodies: &[String], translate: &[String; 3], axis: Option<Vec3>, angle: Option<&String>, copy: bool) {
     let [x, y, z] = translate.clone();
     let mut k = kind(FREE);
     if let Kind::Move { x: kx, y: ky, z: kz, rx, ry, rz, .. } = &mut k {
@@ -311,4 +314,7 @@ pub fn for_feature(d: &mut Dialog, bodies: &[String], translate: &[String; 3], a
     if let Some(inp) = d.inputs.first_mut() {
         inp.items = bodies.iter().map(|n| Sel::Body { name: n.clone() }).collect();
     }
+    if copy {
+        d.extra.insert("copy".into(), json!(true));
+    }
 }