Add option to disable real-time updates in web UI (#9984)

Fix #9031
Fix #7913

app/javascript/mastodon/components/load_pending.js

@@ -0,0 +1,22 @@
+import React from 'react';
+import { FormattedMessage } from 'react-intl';
+import PropTypes from 'prop-types';
+
+export default class LoadPending extends React.PureComponent {
+
+  static propTypes = {
+    onClick: PropTypes.func,
+    count: PropTypes.number,
+  }
+
+  render() {
+    const { count } = this.props;
+
+    return (
+      <button className='load-more load-gap' onClick={this.props.onClick}>
+        <FormattedMessage id='load_pending' defaultMessage='{count, plural, one {# new item} other {# new items}}' values={{ count }} />
+      </button>
+    );
+  }
+
+}