Device manager - current session expandable details (PSG-644) (#9185)

* split current device section into component

* add dropdown button for currentsession device details

* test currentdevicesection

* remove unnecc beforeEach

* update type imports

* i18n and lint

src/components/views/settings/devices/DeviceExpandDetailsButton.tsx

@@ -0,0 +1,41 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+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.
+*/
+
+import classNames from 'classnames';
+import React from 'react';
+
+import { Icon as CaretIcon } from '../../../../../res/img/feather-customised/dropdown-arrow.svg';
+import AccessibleButton from '../../elements/AccessibleButton';
+
+interface Props {
+    isExpanded: boolean;
+    onClick: () => void;
+}
+
+const DeviceExpandDetailsButton: React.FC<Props> = ({ isExpanded, onClick, ...rest }) => {
+    return <AccessibleButton
+        {...rest}
+        kind='icon'
+        className={classNames('mx_DeviceExpandDetailsButton', {
+            mx_DeviceExpandDetailsButton_expanded: isExpanded,
+        })}
+        onClick={onClick}
+    >
+        <CaretIcon className='mx_DeviceExpandDetailsButton_icon' />
+    </AccessibleButton>;
+};
+
+export default DeviceExpandDetailsButton;