Hide CRM Contacts widget when source group has no contacts

What does this MR do and why?

Hides Contacts widget in work item detail view when source group doesn't have any contacts defined.

Note: The widget is only hidden during Work Item show, it will still be displayed for Create View, because the information whether group has CRM contacts available is available only when saved Work Item is fetched, which is not the case for Create View.

References

• !185764 (merged)

Screenshots or screen recordings

	Before	Before (Dropdown)	After
Create View
Detail View

How to set up and validate locally

• Enable CRM contacts on a Group by following docs.
• Visit /groups/<group_name>/-/crm/contacts for the group you enabled CRM, and add a couple of contacts.
• Go to New Issue or existing issue page.
  • With changes in this MR, you should only see Contacts widget if there are contacts present in the group.
  • Without changes in this MR, Contacts widget is always visible even if there are no contacts present.

MR acceptance checklist

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Related to #525875 (closed)