[CodeEditor] add vertical divider

This isn't functional yet.

dist/styles/CodeEditor.css

@@ -93,13 +93,18 @@
   text-transform: inherit;
 }
 .code-editor .editor .v-divider {
+  align-items: center;
   border-left: 1px solid gray;
-  cursor: sw-resize;
-  height: 100%;
+  display: flex;
+  flex-direction: row;
+  justify-content: center;
   margin-left: 5px;
   margin-right: 5px;
   width: 1px;
 }
+.code-editor .editor .v-divider .handle {
+  cursor: ew-resize;
+}
 .code-editor .editor .html {
   flex-grow: 2;
   margin-left: 25px;

dist/styles/CodeEditor.sass

@@ -76,12 +76,16 @@
           @include common-overlay-props()
           @include font-inherit()
     .v-divider
+      align-items: center
       border-left: 1px solid gray
-      cursor: sw-resize
-      height: 100%
+      display: flex
+      flex-direction: row
+      justify-content: center
       margin-left: 5px
       margin-right: 5px
       width: 1px
+      .handle
+        cursor: ew-resize
     .html
       flex-grow: 2
       margin-left: 25px

src/Gargantext/Components/CodeEditor.purs

@@ -124,7 +124,9 @@ codeEditorCpt = R.hooksComponent "G.C.CE.CodeEditor" cpt
                         } []
                ]
              ]
-           , H.div { className: "v-divider " <> (dividerHidden $ fst controls.viewType) } [ H.text " " ]
+           , H.div { className: "v-divider " <> (dividerHidden $ fst controls.viewType) } [
+              H.span { className: "fa fa-bars handle" } []
+            ]
            , H.div { className: "html " <> (langClass $ fst controls.codeType) <> (previewHidden $ fst controls.viewType)
                    , ref: controls.htmlElRef
                    } []