Add Frontend changes to handle new api endpoint

In #214755 (closed) new endpoint was added to expose groups that are eligible for sharing. We need to update the frontend picker so it uses the new endpoint.

Please see #214755 (closed) for details. See also this comment.

Implementation plan

1. Add isProject prop to app/assets/javascripts/invite_members/components/group_select.vue#L26
2. If isProject is true use the new API endpoint in app/assets/javascripts/invite_members/components/group_select.vue#L96