Delete fetchByIid properties in work items

What does this MR do and why?

This MR deletes cleans up some work item components, after !118060 (merged) hardcoded the fetchByIid to true as part of deprecating the work items global ID route.

Follow-up MRs will clean up the rest of the fetchByIid/iid_path code

Issue: #393836 (closed)

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Related to #393836 (closed)