Finish new Message component, integrate into application

Also:
- New schema version 8 with video/image thumbnails, screenshots, sizes
- Upgrade messages not at current schema version when loading messages
  to show in conversation
- New MessageDetail react component
- New ConversationHeader react component

ts/components/conversation/TimerNotification.tsx

@@ -0,0 +1,67 @@
+import React from 'react';
+// import classNames from 'classnames';
+
+import { ContactName } from './ContactName';
+import { Intl } from '../Intl';
+import { Localizer } from '../../types/Util';
+
+import { missingCaseError } from '../../util/missingCaseError';
+
+interface Props {
+  type: 'fromOther' | 'fromMe' | 'fromSync';
+  phoneNumber: string;
+  profileName?: string;
+  name?: string;
+  timespan: string;
+  i18n: Localizer;
+}
+
+export class TimerNotification extends React.Component<Props> {
+  public renderContents() {
+    const { i18n, name, phoneNumber, profileName, timespan, type } = this.props;
+
+    switch (type) {
+      case 'fromOther':
+        return (
+          <Intl
+            i18n={i18n}
+            id="theyChangedTheTimer"
+            components={[
+              <ContactName
+                i18n={i18n}
+                key="external-1"
+                phoneNumber={phoneNumber}
+                profileName={profileName}
+                name={name}
+              />,
+              timespan,
+            ]}
+          />
+        );
+      case 'fromMe':
+        return i18n('youChangedTheTimer', [timespan]);
+      case 'fromSync':
+        return i18n('timerSetOnSync', [timespan]);
+      default:
+        throw missingCaseError(type);
+    }
+  }
+
+  public render() {
+    const { timespan } = this.props;
+
+    return (
+      <div className="module-timer-notification">
+        <div className="module-timer-notification__icon-container">
+          <div className="module-timer-notification__icon" />
+          <div className="module-timer-notification__icon-label">
+            {timespan}
+          </div>
+        </div>
+        <div className="module-timer-notification__message">
+          {this.renderContents()}
+        </div>
+      </div>
+    );
+  }
+}