Unscope and use new pluck_id_and_full_name method

Unscope gets rid of the left outer join with offerer

app/views/admin/projects/_client_contact_fields.html.erb

 <div class="nested-fields list-group-item">
   <div class="row">
     <div class='col-sm-8'>
-      <% staff = User.staff_and_admins.sort_by_name %>
-      <% students = User.role_student.sort_by_name %>
-      <% external = User.role_company.sort_by_name %>
+      <% staff = User.unscoped.staff_and_admins.sort_by_name.pluck_id_and_full_name %>
+      <% students = User.unscoped.role_student.sort_by_name.pluck_id_and_full_name %>
+      <% external = User.unscoped.role_company.sort_by_name.pluck_id_and_full_name %>
       <%= f.grouped_collection_select :id,
                                       %w[Staff Students External],
                                       ->(s) {
@@ -15,7 +15,7 @@
                                           external
                                         end
                                       }, :to_s,
-                                      :id, :name,
+                                      :first, :second,
                                       { prompt: true, selected: f.object&.id },
                                       class: 'selectize' %>
     </div>

app/views/admin/projects/_project_interest_fields.html.erb

@@ -2,7 +2,7 @@
   <div class="row">
     <div class="col-sm-11">
       <%= f.collection_select  :user_id,
-                    User.sort_by_name, :id, :full_name,
+                    User.unscoped.sort_by_name.pluck_id_and_full_name, :first, :second,
                     { prompt: true, selected: f.object.user_id },
                     class: 'selectize' %>
     </div>