Clip commonly seen labels used for display names to prevent Unicode spam

Unfortunately a pretty common spam/annoyance online is putting "spam"
via abusing Unicode symbols - which is used for multilingual support -
in display names. This typically results in an unreadable word jumble in
our UI, which looks bad.

So I decided to put a stop to that by clipping some labels that could be
used for this crap. I didn't cover *everything* yet, but this at least
prevents these idiots from showing up in the completion menu, the room
member list and as authors for messages.

src/messagecontent/AuthorComponent.qml

@@ -49,6 +49,7 @@ RowLayout {
         textFormat: Text.PlainText
         font.weight: Font.Bold
         elide: Text.ElideRight
+        clip: true // Intentional to limit insane Unicode in display names
 
         function openUserMenu(): void {
             const menu = Qt.createComponent("org.kde.neochat", "UserMenu").createObject(root, {