fix(StatusChatInput): don't insert control characters

@mentions have a special `onRelease()` key handler that makes sure a
space is inserted around the mention when needed. Fix the `onRelease()`
handler to prevent control or otherwise unprintable characters being
inserted as text.

Fixes: #7685

ui/imports/shared/status/StatusChatInput.qml

@@ -678,6 +678,9 @@ Rectangle {
     }
 
     function onRelease(event) {
+        if ((event.modifiers & Qt.ControlModifier) || (event.modifiers & Qt.MetaModifier)) // these are likely shortcuts with no meaningful text
+            return
+
         if (event.key === Qt.Key_Backspace && textFormatMenu.opened) {
             textFormatMenu.close()
         }