Event clone: also clone collection/item Uid.

src/Calendars/Calendar.tsx

@@ -66,7 +66,6 @@ class Calendar extends React.PureComponent<PropsType> {
 
           const shift = next.subtractDateTz(event.startDate);
           const ev = event.clone();
-          (ev as any).journalUid = (event as any).journalUid;
           ev.startDate.addDuration(shift);
           ev.endDate.addDuration(shift);
           entries.push(ev);

src/pim-types.ts

@@ -139,6 +139,8 @@ export class EventType extends ICAL.Event implements PimType {
   public clone() {
     const ret = new EventType(ICAL.Component.fromString(this.component.toString()));
     ret.color = this.color;
+    ret.collectionUid = this.collectionUid;
+    ret.itemUid = this.itemUid;
     return ret;
   }
 }