Add user's avatar to the top left of the screen

ts/components/MainHeader.tsx

@@ -0,0 +1,46 @@
+import React from 'react';
+
+import { Avatar } from './Avatar';
+
+import { Localizer } from '../types/Util';
+
+interface Props {
+  phoneNumber: string;
+  isMe?: boolean;
+  name?: string;
+  color?: string;
+  verified: boolean;
+  profileName?: string;
+  avatarPath?: string;
+  i18n: Localizer;
+  onClick?: () => void;
+}
+
+export class MainHeader extends React.Component<Props> {
+  public render() {
+    const {
+      avatarPath,
+      i18n,
+      color,
+      name,
+      phoneNumber,
+      profileName,
+    } = this.props;
+
+    return (
+      <div className="module-main-header">
+        <Avatar
+          avatarPath={avatarPath}
+          color={color}
+          conversationType="direct"
+          i18n={i18n}
+          name={name}
+          phoneNumber={phoneNumber}
+          profileName={profileName}
+          size={28}
+        />
+        <div className="module-main-header__app-name">Signal</div>
+      </div>
+    );
+  }
+}