[FIX]Add min-width on select

On this link you will find the problem explained in the comment by @jonnybradley : https://avan.tech/item68638-Delete-should-not-be-a-default-first-choice-in-an-admin-action-dropdown . I was asked to put a min-width on the select which contains as value "Select the action to be performed with checked..."so that even when the screen size is reduced, the content can still be displayed well and not half as it was. To get an idea, here is the problem in the photo below.

here is the solution now provided, as you can see, the content is displayed in full