Always show custom field dropdown in detail mode

Even if there are no custom fields define, the control is shown now.
The user can create a new one in this view.

modules/webapp/src/main/elm/Comp/ItemDetail/EditForm.elm

@@ -425,5 +425,5 @@ tabState settings allNames model =
     in
     FTabState.tabState settings
         openTabs
-        model.customFieldsModel
+        Nothing
         (.title >> ToggleAkkordionTab)

modules/webapp/src/main/elm/Comp/ItemDetail/FieldTabState.elm

@@ -10,7 +10,7 @@ import Set exposing (Set)
 tabState :
     UiSettings
     -> Set String
-    -> Comp.CustomFieldMultiInput.Model
+    -> Maybe Comp.CustomFieldMultiInput.Model
     -> (TB.Tab msg -> msg)
     -> TB.Tab msg
     -> ( TB.State, msg )
@@ -35,7 +35,9 @@ tabState settings openTabs cfmodel toggle tab =
 
                 "Custom Fields" ->
                     isHidden Data.Fields.CustomFields
-                        || Comp.CustomFieldMultiInput.isEmpty cfmodel
+                        || (Maybe.map Comp.CustomFieldMultiInput.isEmpty cfmodel
+                                |> Maybe.withDefault False
+                           )
 
                 "Date" ->
                     isHidden Data.Fields.Date

modules/webapp/src/main/elm/Comp/ItemDetail/MultiEditMenu.elm

@@ -1149,7 +1149,7 @@ tabState : UiSettings -> Model -> TB.Tab Msg -> ( TB.State, Msg )
 tabState settings model tab =
     FTabState.tabState settings
         model.openTabs
-        model.customFieldModel
+        (Just model.customFieldModel)
         (.title >> ToggleAkkordionTab)
         tab