fix: Add new HTML and JS files for issue #322 investigation.

- Created `322.html` which includes a select component for identifying issues with selecting an integer and an empty value.
- Added `322.mjs` script for handling the necessary imports and functionalities related to the select element.
- Introduced `issue-322.js` mock data file to simulate responses for testing the new functionality.
- Refactored some parts of existing `select.mjs` file to maintain coding consistency.
- The changes provide a clearer interface for understanding the interactions that occur when empty values are involved with the integer-select feature, facilitating debugging and further development.