[Glitch] Rename JSX files with proper .jsx extension

Port 44a7d87cb1 to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/components/column_back_button_slim.jsx

@@ -0,0 +1,37 @@
+import React from 'react';
+import { FormattedMessage } from 'react-intl';
+import PropTypes from 'prop-types';
+import Icon from 'flavours/glitch/components/icon';
+
+export default class ColumnBackButtonSlim extends React.PureComponent {
+
+  static contextTypes = {
+    router: PropTypes.object,
+  };
+
+  handleClick = (event) => {
+    // if history is exhausted, or we would leave mastodon, just go to root.
+    if (window.history.state) {
+      const state = this.context.router.history.location.state;
+      if (event.shiftKey && state && state.mastodonBackSteps) {
+        this.context.router.history.go(-state.mastodonBackSteps);
+      } else {
+        this.context.router.history.goBack();
+      }
+    } else {
+      this.context.router.history.push('/');
+    }
+  };
+
+  render () {
+    return (
+      <div className='column-back-button--slim'>
+        <div role='button' tabIndex='0' onClick={this.handleClick} className='column-back-button column-back-button--slim-button'>
+          <Icon id='chevron-left' className='column-back-button__icon' fixedWidth />
+          <FormattedMessage id='column_back_button.label' defaultMessage='Back' />
+        </div>
+      </div>
+    );
+  }
+
+}