Remove unused ColumnBackButton component

app/soapbox/components/__tests__/column_back_button.test.js

@@ -1,12 +0,0 @@
-import React from 'react';
-
-import { render, screen } from '../../jest/test-helpers';
-import ColumnBackButton from '../column_back_button';
-
-describe('<ColumnBackButton />', () => {
-  it('renders correctly', () => {
-    render(<ColumnBackButton />);
-
-    expect(screen.getByRole('button')).toHaveTextContent('Back');
-  });
-});

app/soapbox/components/column_back_button.js

@@ -1,41 +0,0 @@
-import PropTypes from 'prop-types';
-import React from 'react';
-import { FormattedMessage } from 'react-intl';
-import { withRouter } from 'react-router-dom';
-
-import Icon from 'soapbox/components/icon';
-
-export default @withRouter
-class ColumnBackButton extends React.PureComponent {
-
-  static propTypes = {
-    to: PropTypes.string,
-    history: PropTypes.object,
-  };
-
-  handleClick = () => {
-    const { to } = this.props;
-
-    if (window.history?.length === 1) {
-      this.props.history.push(to ? to : '/');
-    } else {
-      this.props.history.goBack();
-    }
-  }
-
-  handleKeyUp = (e) => {
-    if (e.key === 'Enter') {
-      this.handleClick();
-    }
-  }
-
-  render() {
-    return (
-      <button onClick={this.handleClick} onKeyUp={this.handleKeyUp} className='column-back-button'>
-        <Icon id='chevron-left' className='column-back-button__icon' fixedWidth />
-        <FormattedMessage id='column_back_button.label' defaultMessage='Back' />
-      </button>
-    );
-  }
-
-}

app/soapbox/features/chats/chat_room.js

@@ -77,7 +77,6 @@ class ChatRoom extends ImmutablePureComponent {
     return (
       <Column label={`@${getAcct(account, displayFqn)}`}>
         {/* <div className='chatroom__back'>
-          <ColumnBackButton />
           <Link to={`/@${account.get('acct')}`} className='chatroom__header'>
             <Avatar account={account} size={18} />
             <div className='chatroom__title'>