codemirror: define `hanging_indent: 4` for python

to match what yapf is doing

bt5/erp5_code_mirror/SkinTemplateItem/portal_skins/erp5_code_mirror/code_mirror_support.txt

@@ -240,7 +240,7 @@
      generateHistorySelectElement();
 
      /* check getTextContent have not changed server side (for example YAPF) */
-     if (mode == 'python') {
+     if (mode === 'python' || (mode && mode.name === 'python')) {
        $.ajax({
          type: 'GET',
          url: 'getTextContent',
@@ -347,7 +347,7 @@
 
  function saveZMIDocument(cm, event) {
    /* preformat with YAPF before saving */
-   if (mode == 'python') {
+   if (mode === 'python' || (mode && mode.name === 'python')) {
      $.ajax({
        type: 'POST',
        url: '&dtml-portal_url;/ERP5Site_formatPythonSourceCode',
@@ -514,6 +514,10 @@
 <dtml-if expr="mode == 'python'">
  lint_option = {"getAnnotations": checkPythonSourceCode,
                 "async": true};
+ mode = {
+   name: "python",
+   hangingIndent: 4
+ }
 <dtml-elif expr="mode in ('css', 'javascript')">
  lint_option = true;
 <dtml-else>