Add canInviteMembers to work item assignees widget

What does this MR do and why?

Add canInviteMembers to work item assignees widget

This is needed to render the invite modal within the assignees widget

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.

Related to #334810 (closed)