[MM-59483] Remove legacy preload and custom login code (#3174)

* Remove legacy preload script code

* Remove custom login code

* FIx i18n

src/renderer/components/ExtraBar.tsx

@@ -1,53 +0,0 @@
-// Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
-// See LICENSE.txt for license information.
-
-import React from 'react';
-import {Row, Button} from 'react-bootstrap';
-import {FormattedMessage} from 'react-intl';
-
-type Props = {
-    darkMode?: boolean;
-    goBack?: () => void;
-    show?: boolean;
-};
-
-export default class ExtraBar extends React.PureComponent<Props> {
-    handleBack = () => {
-        if (this.props.goBack) {
-            this.props.goBack();
-        }
-    };
-    render() {
-        let barClass = 'clear-mode';
-        if (!this.props.show) {
-            barClass = 'hidden';
-        } else if (this.props.darkMode) {
-            barClass = 'dark-mode';
-        }
-
-        return (
-            <Row
-                id={'extra-bar'}
-                className={barClass}
-            >
-                <div
-                    className={'container-fluid'}
-                    onClick={this.handleBack}
-                >
-                    <Button
-                        variant={'link'}
-                        size={'sm'}
-                    >
-                        <span className={'backIcon icon-arrow-left'}/>
-                        <span className={'backLabel'}>
-                            <FormattedMessage
-                                id='renderer.components.extraBar.back'
-                                defaultMessage='Back'
-                            />
-                        </span>
-                    </Button>
-                </div>
-            </Row>
-        );
-    }
-}

src/renderer/components/MainPage.tsx

@@ -15,7 +15,6 @@ import type {DownloadedItems} from 'types/downloads';
 import DeveloperModeIndicator from './DeveloperModeIndicator';
 import DownloadsDropdownButton from './DownloadsDropdown/DownloadsDropdownButton';
 import ErrorView from './ErrorView';
-import ExtraBar from './ExtraBar';
 import ServerDropdownButton from './ServerDropdownButton';
 import TabBar from './TabBar';
 
@@ -50,7 +49,6 @@ type State = {
     tabViewStatus: Map<string, TabViewStatus>;
     modalOpen?: boolean;
     fullScreen?: boolean;
-    showExtraBar?: boolean;
     isMenuOpen: boolean;
     isDownloadsDropdownOpen: boolean;
     showDownloadsBadge: boolean;
@@ -210,10 +208,6 @@ class MainPage extends React.PureComponent<Props, State> {
             this.setState({modalOpen: false});
         });
 
-        window.desktop.onToggleBackButton((showExtraBar) => {
-            this.setState({showExtraBar});
-        });
-
         window.desktop.onUpdateMentions((view, mentions, unreads, isExpired) => {
             const {unreadCounts, mentionCounts, sessionsExpired} = this.state;
 
@@ -532,13 +526,6 @@ class MainPage extends React.PureComponent<Props, State> {
 
         const viewsRow = (
             <Fragment>
-                <ExtraBar
-                    darkMode={this.props.darkMode}
-                    show={this.state.showExtraBar}
-                    goBack={() => {
-                        window.desktop.goBack();
-                    }}
-                />
                 <Row>
                     {views()}
                 </Row>