TF-3627 Fix two scrollbar with different look

Signed-off-by: dab246 <tdvu@linagora.com>

core/lib/utils/html/html_template.dart

@@ -218,4 +218,35 @@ class HtmlTemplate {
   ''';
 
   static const String markDownAndASCIIArtStyleCSS = 'display: block; font-family: monospace; white-space: pre; margin: 1em 0px;';
+
+  static const String customInternalStyleCSS = '''
+    <style>
+      * {
+        overflow: auto;
+      }
+      
+      *::-webkit-scrollbar {
+        width: 8px;
+        height: 8px;
+      }
+
+      *::-webkit-scrollbar-thumb {
+        background-color: #c1c1c1;
+        border-radius: 10px;
+        min-height: 70px;
+      }
+      
+      *::-webkit-scrollbar-track {
+        background: transparent;
+        border-radius: 10px;
+      }
+      
+      /* Browsers without `::-webkit-scrollbar-*` support */
+      @supports not selector(::-webkit-scrollbar) {
+          * {
+            scrollbar-color: #c1c1c1 transparent;
+          }
+      }
+    </style>
+  ''';
 }

lib/features/composer/presentation/widgets/web/web_editor_widget.dart

@@ -2,6 +2,7 @@ import 'dart:convert';
 
 import 'package:collection/collection.dart';
 import 'package:core/utils/app_logger.dart';
+import 'package:core/utils/html/html_template.dart';
 import 'package:core/utils/html/html_utils.dart';
 import 'package:flutter/material.dart';
 import 'package:html_editor_enhanced/html_editor.dart';
@@ -118,6 +119,7 @@ class _WebEditorState extends State<WebEditorWidget> {
         darkMode: false,
         initialText: widget.content,
         customBodyCssStyle: HtmlUtils.customCssStyleHtmlEditor(direction: widget.direction),
+        customInternalCSS: HtmlTemplate.customInternalStyleCSS,
         spellCheck: true,
         disableDragAndDrop: true,
         webInitialScripts: UnmodifiableListView([

pubspec.lock

@@ -1235,11 +1235,11 @@ packages:
     dependency: "direct main"
     description:
       path: "."
-      ref: main
-      resolved-ref: "0ba81a166219f227aec70d562ab06daedf793608"
+      ref: custom-internal-css
+      resolved-ref: "7ba66dc9cee4e6c202be93ee6afa8a0f3a4c0415"
       url: "https://github.com/linagora/html-editor-enhanced.git"
     source: git
-    version: "3.1.5"
+    version: "3.1.6"
   http:
     dependency: transitive
     description:

pubspec.yaml

@@ -60,7 +60,7 @@ dependencies:
   html_editor_enhanced:
     git:
       url: https://github.com/linagora/html-editor-enhanced.git
-      ref: main
+      ref: custom-internal-css
 
   jmap_dart_client:
     git: