[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/features/ui/components/column_loading.jsx

@@ -0,0 +1,32 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+
+import Column from 'flavours/glitch/components/column';
+import ColumnHeader from 'flavours/glitch/components/column_header';
+import ImmutablePureComponent from 'react-immutable-pure-component';
+
+export default class ColumnLoading extends ImmutablePureComponent {
+
+  static propTypes = {
+    title: PropTypes.oneOfType([PropTypes.node, PropTypes.string]),
+    icon: PropTypes.string,
+    multiColumn: PropTypes.bool,
+  };
+
+  static defaultProps = {
+    title: '',
+    icon: '',
+  };
+
+  render() {
+    let { title, icon, multiColumn } = this.props;
+
+    return (
+      <Column>
+        <ColumnHeader icon={icon} title={title} multiColumn={multiColumn} focusable={false} placeholder />
+        <div className='scrollable' />
+      </Column>
+    );
+  }
+
+}