Fix room banners height

TODO.md

@@ -10,6 +10,7 @@
   - Sending `![A picture](https://picsum.photos/256/256)` → not clickable?
   - Icons, images and HStyle singleton aren't reloaded
   - `MessageDelegate.qml:63: TypeError: 'reloadPreviousItem' not a function`
+  - RoomEventsList scrolling when resizing the window
 
 - UI
   - Accounts delegates background

harmonyqml/components/Chat/Banners/Banner.qml

@@ -5,7 +5,7 @@ import "../../Base"
 HRectangle {
     id: banner
     Layout.fillWidth: true
-    Layout.preferredHeight: HStyle.avatar.size
+    Layout.preferredHeight: HStyle.bottomElementsHeight
 
     property alias avatar: bannerAvatar
     property alias icon: bannerIcon