bring back user page

Adds a UserView that contains a MainSplit with an empty div
and a RightPanel, preset to the given member.

UserView fetches the profile and creates a fake member, which
it passed on to the RightPanel.

this doesn't use the view_user action on purpose, to avoid any
interference of the UserView when trying to view a room member.

src/components/structures/UserView.js

@@ -0,0 +1,77 @@
+/*
+Copyright 2019 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.
+*/
+
+import React from "react";
+import Matrix from "matrix-js-sdk";
+import MatrixClientPeg from "../../MatrixClientPeg";
+import sdk from "../../index";
+
+
+export default class UserView extends React.Component {
+    static get propTypes() {
+        return {
+            userId: React.PropTypes.string,
+        };
+    }
+
+    constructor(props) {
+        super(props);
+        this.state = {};
+    }
+
+    componentWillMount() {
+        if (this.props.userId) {
+            this._loadProfileInfo();
+        }
+    }
+
+    componentDidUpdate(prevProps) {
+        if (prevProps.userId !== this.props.userId) {
+            this._loadProfileInfo();
+        }
+    }
+
+    async _loadProfileInfo() {
+        const cli = MatrixClientPeg.get();
+        this.setState({loading: true});
+        let profileInfo;
+        try {
+            profileInfo = await cli.getProfileInfo(this.props.userId);
+        } catch (err) {
+            // show dialog or error or something
+            this.setState({loading: false});
+            return;
+        }
+        const fakeEvent = new Matrix.MatrixEvent({type: "m.room.member", content: profileInfo});
+        const member = new Matrix.RoomMember(null, this.props.userId);
+        member.setMembershipEvent(fakeEvent);
+        this.setState({member, loading: false});
+    }
+
+    render() {
+        if (this.state.loading) {
+            const Spinner = sdk.getComponent("elements.Spinner");
+            return <Spinner />;
+        } else if (this.state.member) {
+            const RightPanel = sdk.getComponent('structures.RightPanel');
+            const MainSplit = sdk.getComponent('structures.MainSplit');
+            const panel = <RightPanel user={this.state.member} />;
+            return (<MainSplit panel={panel}><div style={{flex: "1"}} /></MainSplit>);
+        } else {
+            return (<div />);
+        }
+    }
+}