A Sketch Scale window, replacing a toolbar button that only raised an engine error (#733)

Sketch Scale now opens a tool window with the entities, an optional base point and a typed factor, instead of running the command with no parameters and raising an engine error.

crates/ui-egui/src/lib.rs

@@ -105,6 +105,9 @@ mod sketch_drag_ui_tests;
 #[cfg(test)]
 mod sketch_edit_tests;
 mod sketch_families;
+pub mod sketch_modify_ui;
+#[cfg(test)]
+mod sketch_modify_ui_tests;
 pub mod sketch_palette;
 pub(crate) mod sketch_text;
 mod sketch_text_move;