Sdoc (#5434)

* [sdoc file view] added file view, history/trash file view for 'sdoc'

* [sdoc file view] sdoc-editor: upgraded it to the latest version(0.1.5)

- sdoc file view: enable 'auto save'
- sdoc shared/history/trash file view: use the read-only sdoc viewer

* [sdoc file view] fixup

frontend/src/components/file-content-view/sdoc.js

@@ -0,0 +1,20 @@
+import React from 'react';
+import { SDocViewer } from '@seafile/sdoc-editor';
+import { defaultContentForSDoc } from '../../utils/constants';
+
+import '../../css/sdoc-file-view.css';
+
+const { fileContent } = window.app.pageOptions;
+
+class FileContent extends React.Component {
+
+  render() {
+    return (
+      <div className="file-view-content flex-1 o-auto sdoc-file-view p-0 d-flex flex-column">
+        <SDocViewer document={fileContent ? JSON.parse(fileContent) : defaultContentForSDoc} config={{}} />
+      </div>
+    );
+  }
+}
+
+export default FileContent;