MessageEventModel plain text role

Update the message role to be named plainText and use it the message delegate for openMessageContext.
This removes the need for plainText in controller so it is removed.

src/models/messageeventmodel.cpp

@@ -34,7 +34,7 @@ QHash<int, QByteArray> MessageEventModel::roleNames() const
 {
     QHash<int, QByteArray> roles = QAbstractItemModel::roleNames();
     roles[DelegateTypeRole] = "delegateType";
-    roles[MessageRole] = "message";
+    roles[PlainText] = "plainText";
     roles[EventIdRole] = "eventId";
     roles[TimeRole] = "time";
     roles[SectionRole] = "section";
@@ -493,7 +493,7 @@ QVariant MessageEventModel::data(const QModelIndex &idx, int role) const
         return {};
     }
 
-    if (role == MessageRole) {
+    if (role == PlainText) {
         return m_currentRoom->eventToString(evt);
     }
 

src/models/messageeventmodel.h

@@ -58,7 +58,7 @@ public:
      */
     enum EventRoles {
         DelegateTypeRole = Qt::UserRole + 1, /**< The delegate type of the message. */
-        MessageRole, /**< Plain text representation of the message. */
+        PlainText, /**< Plain text representation of the message. */
         EventIdRole, /**< The matrix event ID of the event. */
         TimeRole, /**< The timestamp for when the event was sent. */
         SectionRole, /**< The date of the event as a string. */