Work item hierarchy - Prevent dropping in orphan child when type is not allowed

What does this MR do and why?

Work item hierarchy - Prevent dropping in child when type is not allowed in an orphan child.

For example, a task cannot be a child of an epic. So if an epic has no children and the user is dragging a task, the dropzone won't appear under the epic. However, it will allow dropping an issue in the same epic.

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Screenshots or screen recordings

Screen_Recording_2024-10-11_at_4.48.55_PM

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Related to #482531 (closed)