Only show applicable work items in autosuggest for parent/child quick actions

Summary

When using /set_parent or /add_child the autosuggest returns all work items, including invalid selections that result in an error when applied.

The list of autosuggested work items should be the same list used in the parent widget. Specifically this should:

• Exclude the current item
• Exclude items whose type cannot be a parent of the current item (i.e. tasks)