fix(multi-select): module not working when using basic HTTP form transport

### Issue

When using `multiselect` module in a basic HTTP form (sending data via basic HTTP, not AJAX)
The "name" attribute given to `multiselect` options  was on the `<select>` used for selecting item, not on inputs containing data.

### Fix

Set a random name to the `<select>` and set proper name to the DDList inputs