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/SafetyNumberNotification.tsx

@@ -0,0 +1,58 @@
+import React from 'react';
+// import classNames from 'classnames';
+
+import { ContactName } from './ContactName';
+import { Intl } from '../Intl';
+import { Localizer } from '../../types/Util';
+
+interface Contact {
+  phoneNumber: string;
+  profileName?: string;
+  name?: string;
+}
+
+interface Props {
+  isGroup: boolean;
+  contact: Contact;
+  i18n: Localizer;
+  onVerify: () => void;
+}
+
+export class SafetyNumberNotification extends React.Component<Props> {
+  public render() {
+    const { contact, isGroup, i18n, onVerify } = this.props;
+
+    return (
+      <div className="module-safety-number-notification">
+        <div className="module-safety-number-notification__icon" />
+        <div className="module-safety-number-notification__text">
+          <Intl
+            id={isGroup ? 'safetyNumberChangedGroup' : 'safetyNumberChanged'}
+            components={[
+              <span
+                key="external-1"
+                className="module-safety-number-notification__contact"
+              >
+                <ContactName
+                  i18n={i18n}
+                  name={contact.name}
+                  profileName={contact.profileName}
+                  phoneNumber={contact.phoneNumber}
+                  module="module-verification-notification__contact"
+                />
+              </span>,
+            ]}
+            i18n={i18n}
+          />
+        </div>
+        <div
+          role="button"
+          onClick={onVerify}
+          className="module-verification-notification__button"
+        >
+          {i18n('verifyNewNumber')}
+        </div>
+      </div>
+    );
+  }
+}