Update state and proposals only on invalid items

Invalid items are those that are not ready, and not shown to the user.
When changing metadata, it should only be changed, if the item was not
already shown to the user.

modules/restserver/src/main/scala/docspell/restserver/conv/Conversions.scala

@@ -109,7 +109,7 @@ trait Conversions {
       coll,
       m.name,
       if (m.inbox) Seq(ItemState.Created)
-      else ItemState.validStates,
+      else ItemState.validStates.toList,
       m.direction,
       m.corrPerson,
       m.corrOrg,