Add `Epic` type filter on Issues dashboard
What does this MR do and why?
Add support for filtering Issues Dashboard by Epic type now that Epic Work Items support assignees.
MR acceptance checklist
Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.
Screenshots or screen recordings
How to set up and validate locally
TBA
Related to #238440