rename TopLeftMenu to TopLeftMenuButton

so the former can be the actual menu

res/css/structures/_TopLeftMenuButton.scss

@@ -0,0 +1,41 @@
+/*
+Copyright 2018 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_TopLeftMenuButton {
+    height: 52px;
+    border-bottom: 1px solid $panel-divider-color;
+    color: $topleftmenu-color;
+    background-color: $primary-bg-color;
+    display: flex;
+}
+
+.mx_TopLeftMenuButton_avatar {
+    position: relative; // to get avatar in the right place
+    margin-left: 15px;
+    margin-right: 15px;
+    margin-top: 14px;
+}
+
+.mx_TopLeftMenuButton_name {
+    margin-top: 15px;
+    margin-right: 9px;
+    font-size: 18px;
+    font-weight: 600;
+}
+
+.mx_TopLeftMenuButton_chevron {
+    margin-top: 24px;
+}