Add work item discussion filter

What does this MR do and why?

Adds a work item discussion filter for filtering on notes and comments.

Screenshots or screen recordings

Screen_Recording_2023-02-23_at_5.03.11_PM

How to set up and validate locally

1. Enable the work_items_mvc flag

   Feature.enable(:work_items_mvc)

2. Open any task such as http://127.0.0.1:3000/flightjs/Flight/-/work_items/636
3. See the newly added filter on work items activity , it is saved in local storage so that it saved the last time you use it

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.

Related to #389971 (closed)