Add clamp_to_range option to DragValue, rename clamp_range to range (deprecating the former) (#4728)

Adds the ability to have `DragValue` not clamp values its presented with
and instead apply clamping only once there's any user input.

In action:


https://github.com/emilk/egui/assets/1220815/af42fd67-86d0-4364-8ae6-48a2ec15646a




Alternative name could be `only_clamp_on_change`, not entirely certain
which one is better 🤔

crates/egui_demo_lib/src/demo/code_example.rs

@@ -43,15 +43,11 @@ impl CodeExample {
             r#"
             ui.add(
                 egui::DragValue::new(age)
-                    .clamp_range(0..=120)
+                    .range(0..=120)
                     .suffix(" years"),
             );"#,
         );
-        ui.add(
-            egui::DragValue::new(age)
-                .clamp_range(0..=120)
-                .suffix(" years"),
-        );
+        ui.add(egui::DragValue::new(age).range(0..=120).suffix(" years"));
         ui.end_row();
 
         show_code(