Improve SidePane auto-sizing and appearance

harmonyqml/components/Chat/Banners/Banner.qml

@@ -5,7 +5,7 @@ import "../../Base"
 HRectangle {
     id: banner
     Layout.fillWidth: true
-    Layout.preferredHeight: 32
+    Layout.preferredHeight: HStyle.avatar.size
 
     property alias avatar: bannerAvatar
     property alias icon: bannerIcon

harmonyqml/components/Chat/Chat.qml

@@ -38,7 +38,7 @@ HColumnLayout {
         topic: roomInfo.topic || ""
 
         Layout.fillWidth: true
-        Layout.preferredHeight: 32
+        Layout.preferredHeight: HStyle.avatar.size
     }
 
 
@@ -82,7 +82,7 @@ HColumnLayout {
             property int referenceWidth: roomHeader.buttonsWidth
             onReferenceWidthChanged: width = referenceWidth
 
-            Layout.minimumWidth: 36
+            Layout.minimumWidth: HStyle.avatar.size
             Layout.maximumWidth: parent.width
         }
     }

harmonyqml/components/Chat/SendBox.qml

@@ -7,7 +7,7 @@ HRectangle {
 
     id: root
     Layout.fillWidth: true
-    Layout.minimumHeight: 32
+    Layout.minimumHeight: HStyle.bottomElementsHeight
     Layout.preferredHeight: textArea.implicitHeight
     // parent.height / 2 causes binding loop?
     Layout.maximumHeight: pageStack.height / 2