fix(select): select check additional count event loop (#743)

Fixes select causing the window to be frozen on choosing x amount of
options. This is caused by running `_checkAdditionalItemCount` within
updated for each update instead of listening for selected options only.

Co-authored-by: Aykut Saraç <[email protected]>

Author: AykutSarac

src/components/select/bl-select.ts

@@ -488,7 +488,9 @@ export default class BlSelect<ValueType extends FormValue = string> extends Form
       this.value = null;
     }
 
-    this._checkAdditionalItemCount();
+    if (_changedProperties.has("_selectedOptions")) {
+      this._checkAdditionalItemCount();
+    }
   }
 
   /**