Iterations bug fixed for task without a parent

What does this MR do and why?

_This MR fixes a bug wherein the injected flags hasIterationsFeature and projectNamespace are not available in work_item_detail_modal.vue when opened via related issues from issue detail page. _

Screenshots or screen recordings

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Enable the flag

   Feature.enable(:work_items_mvc_2)

2. Create a new task by visiting the url - http://127.0.0.1:3000/gitlab-org/gitlab-test/-/work_items/new
3. Now go to any issue and open the full issue detail page
4. Go to the Linked Items section and link the orphan task that you just created by searching/using iid
5. Click on the link to open the task and you will see that a modal is opened.
6. You should be able to see the iterations in the modal.

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.