Add UX Issue template

What does this MR do and why?

This issue template is for teams who create separate UX issues and/or teams who create a new feature issue but don't use the Feature request template.

This is being created primarily on request by the Fulfillment UX team, but if people like it, more teams can use it!

Screenshots or screen recordings

NA

How to set up and validate locally

NA

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.