feat: Allow viewers to be upgraded to editors on individual collections (#4023)

* Improve types

* More types, fix default permission for viewers added to collection

* fix change of default role for CollectionGroup

* Restore policy

* test

* tests

app/scenes/CollectionPermissions/AddPeopleToCollection.tsx

@@ -57,7 +57,6 @@ class AddPeopleToCollection extends React.Component<Props> {
       this.props.memberships.create({
         collectionId: this.props.collection.id,
         userId: user.id,
-        permission: "read_write",
       });
       this.props.toasts.showToast(
         t("{{ userName }} was added to the collection", {