Fix avatar loading in multiple places and prefers name instead of

display name for avatar fallback.

This also fixes a bug where users didn't get their avatar loaded in the
room list.

Fix #209

imports/NeoChat/Component/Timeline/ReplyComponent.qml

@@ -31,7 +31,7 @@ QQC2.AbstractButton {
             Layout.alignment: Qt.AlignTop
             visible: Config.showAvatarInTimeline
             source: replyVisible && reply.author.avatarMediaId ? ("image://mxc/" + reply.author.avatarMediaId) : ""
-            name: replyVisible ? reply.author.displayName : "H"
+            name: replyVisible ? reply.author.name : "H"
             color: replyVisible ? reply.author.color : Kirigami.Theme.highlightColor
         }