codemirror: hide the drop down to select history when maximized

The real motivation was to make sure that search match is displayed when searching with Ctrl+F / Ctrl+G
(cherry picked from commit 24a171a4)

bt5/erp5_code_mirror/SkinTemplateItem/portal_skins/erp5_code_mirror/code_mirror_support.xml

@@ -338,6 +338,7 @@
 \n
  function switchToFullScreen(cm) {\n
    element = $(\'#merge\')[0];\n
+   $("#history_select_container").hide()\n
    $(cm.getWrapperElement()).css(\'height\', \'100%\');\n
    if((document.fullScreenElement &&\n
        document.fullScreenElement !== null) ||\n
@@ -360,6 +361,7 @@
  function maximize() {\n
    document.documentElement.style.overflow = "hidden";\n
    $("#merge").addClass(\'maximize\');\n
+   $("#history_select_container").hide()\n
 \n
    if(merge_mode_elem) {\n
      $("#view").height("100%");\n
@@ -396,6 +398,7 @@
 \n
          document.documentElement.style.overflow = "";\n
          $("#merge").removeClass(\'maximize\');\n
+         $("#history_select_container").show()\n
 \n
          if(merge_mode_elem) {\n
            $(\'.CodeMirror-merge\').height(cm_merge_height);\n