add cancel button

[three-water666]

I have identified a few existing issues:

1. The popup after selecting an element lacks a cancel button. If the input is empty and you click submit, you cannot continue selecting a new element.
2. If you fill in the input and submit, you can still continue to select , but icon's state changes.

So, I did the following work: added a cancel button and improved the logic in this part. If you click the cancel button, you can continue selecting elements. If you click submit, you need to trigger the process again.