Convert CommonJS exports to ES6-compatible exports

We use `export default` begrudgingly here. Ideally we'd use just `export`, though this entire SDK expects things to be exported as a default. Instead of breaking everything, we'll sacrifice our export pattern for a smaller diff - a later commit can always do the default export -> regular export conversion.

src/components/views/messages/MFileBody.js

@@ -194,7 +194,7 @@ function computedStyle(element) {
     return cssText;
 }
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'MFileBody',
 
     getInitialState: function() {

src/components/views/messages/MVideoBody.js

@@ -1,5 +1,6 @@
 /*
 Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2019 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.
@@ -23,7 +24,7 @@ import { decryptFile } from '../../../utils/DecryptFile';
 import { _t } from '../../../languageHandler';
 import SettingsStore from "../../../settings/SettingsStore";
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'MVideoBody',
 
     propTypes: {

src/components/views/messages/MessageEvent.js

@@ -21,7 +21,7 @@ import sdk from '../../../index';
 import SettingsStore from "../../../settings/SettingsStore";
 import {Mjolnir} from "../../../mjolnir/Mjolnir";
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'MessageEvent',
 
     propTypes: {

src/components/views/messages/RoomAvatarEvent.js

@@ -1,6 +1,7 @@
 /*
 Copyright 2017 Vector Creations Ltd
 Copyright 2019 Michael Telatynski <7t3chguy@gmail.com>
+Copyright 2019 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.
@@ -24,7 +25,7 @@ import sdk from '../../../index';
 import Modal from '../../../Modal';
 import AccessibleButton from '../elements/AccessibleButton';
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'RoomAvatarEvent',
 
     propTypes: {

src/components/views/messages/RoomCreate.js

@@ -1,5 +1,6 @@
 /*
 Copyright 2018 New Vector Ltd
+Copyright 2019 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.
@@ -23,7 +24,7 @@ import { RoomPermalinkCreator } from '../../../utils/permalinks/Permalinks';
 import { _t } from '../../../languageHandler';
 import MatrixClientPeg from '../../../MatrixClientPeg';
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'RoomCreate',
 
     propTypes: {

src/components/views/messages/TextualBody.js

@@ -35,7 +35,7 @@ import {IntegrationManagers} from "../../../integrations/IntegrationManagers";
 import {isPermalinkHost} from "../../../utils/permalinks/Permalinks";
 import {toRightOf} from "../../structures/ContextMenu";
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'TextualBody',
 
     propTypes: {

src/components/views/messages/TextualEvent.js

@@ -1,5 +1,6 @@
 /*
 Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2019 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.
@@ -20,7 +21,7 @@ import createReactClass from 'create-react-class';
 
 const TextForEvent = require('../../../TextForEvent');
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'TextualEvent',
 
     propTypes: {

src/components/views/messages/UnknownBody.js

@@ -18,7 +18,7 @@ import React from 'react';
 import createReactClass from 'create-react-class';
 import { _t } from '../../../languageHandler';
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'UnknownBody',
 
     render: function() {