fix(select): do not dispatch "change" event on initial load (#1356)

Follow-up to #1353

If `selected` is `undefined` or not provided, the "change" event will be dispatched since the first `SelectItem` value will be set as the default.

The "change" event should only be dispatched when the value is actually changed.

src/Select/Select.svelte

@@ -108,9 +108,16 @@
     selectedValue.set(value);
   };
 
+  let prevSelected = undefined;
+
   afterUpdate(() => {
     selected = $selectedValue;
-    dispatch("change", $selectedValue);
+
+    if (prevSelected !== undefined && selected !== prevSelected) {
+      dispatch("change", $selectedValue);
+    }
+
+    prevSelected = selected;
   });
 
   $: errorId = `error-${id}`;