Remove the now unused author ID role from MessageEventModel

Remove the now unused author ID role from `MessageEventModel`. This can be obtained from the author roles object.

src/models/messageeventmodel.cpp

@@ -55,7 +55,6 @@ QHash<int, QByteArray> MessageEventModel::roleNames() const
     roles[ShowReadMarkersRole] = "showReadMarkers";
     roles[ReactionRole] = "reaction";
     roles[ShowReactionsRole] = "showReactions";
-    roles[AuthorIdRole] = "authorId";
     roles[VerifiedRole] = "verified";
     roles[AuthorDisplayNameRole] = "authorDisplayName";
     roles[IsRedactedRole] = "isRedacted";
@@ -659,10 +658,6 @@ QVariant MessageEventModel::data(const QModelIndex &idx, int role) const
         return m_reactionModels.contains(evt.id());
     }
 
-    if (role == AuthorIdRole) {
-        return evt.senderId();
-    }
-
     if (role == VerifiedRole) {
         if (evt.originalEvent()) {
             auto encrypted = dynamic_cast<const EncryptedEvent *>(evt.originalEvent());

src/models/messageeventmodel.h

@@ -73,8 +73,6 @@ public:
         ReactionRole, /**< List model for this event. */
         ShowReactionsRole, /**< Whether there are any reactions to be shown. */
 
-        AuthorIdRole, /**< Matrix ID of the message author. */
-
         VerifiedRole, /**< Whether an encrypted message is sent in a verified session. */
         AuthorDisplayNameRole, /**< The displayname for the event's sender; for name change events, the old displayname. */
         IsRedactedRole, /**< Whether an event has been deleted. */