Add health status selection widget for work items

What does this MR do and why?

Makes it possible to change the health status of a work item in the UI.

Screenshots or screen recordings

health_status_new

How to set up and validate locally

1. Enable OKRs Feature.enable(:okrs_mvc)
2. Go to issue list and create an objective (On the "new issue" button top right, there is a dropdown to create an objective)
3. Change the Health Status of the objective

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.