Redirect to consolidated list when FF is enabled

Issue: Redirect from issues and epics route to work it... (#513115)

What does this MR do and why?

Redirects /issues and /epics to the /work_items page when the work_item_planning_view FF is enabled.

Preserves all filtering options, additionally adds type = issue or type = epic depending on the original url

References

Screenshots or screen recordings

Before	After
Screen_Recording_2025-10-29_at_7.21.03_PM	Screen_Recording_2025-10-29_at_7.17.26_PM

How to set up and validate locally

1. Turn on the feature_flag work_item_planning_view

2. Go to a group issues page:

   http://gdk.test:3000/groups/<your-group>/-/issues?sort=created_date&state=all&first_page_size=20

3. Confirm that it gets redirected to:

   http://gdk.test:3000/groups/<your-group>/-/work_items?sort=created_date&state=all&type%5B%5D=issue&first_page_size=20

MR acceptance checklist

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Related to #513115