fix: custom emote placeholder

- place emote loading spinner in the position as the emote itself
- add key to preview in order to ensure proper states aligned

Signed-off-by: TheOneWithTheBraid <the-one@with-the-braid.cf>

lib/pages/chat/input_bar.dart

@@ -263,6 +263,8 @@ class InputBar extends StatelessWidget {
           crossAxisAlignment: CrossAxisAlignment.center,
           children: <Widget>[
             MxcImage(
+              // ensure proper ordering ...
+              key: ValueKey(suggestion['name']),
               uri: suggestion['mxc'] is String
                   ? Uri.parse(suggestion['mxc'] ?? '')
                   : null,