Add tooltip to epic actions dropdown

What does this MR do and why?

Adds tooltip to Epic actions dropdown

Screenshots or screen recordings

How to set up and validate locally

• Go to epic
• Hover over ellipsis button in top right corner

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.