TF-1486 Add insert image in signature on web

(cherry picked from commit 50f0e54b2a47fe2e857372f56293d1c1800ded2b)

lib/features/composer/presentation/controller/rich_text_web_controller.dart

@@ -1,7 +1,10 @@
 
+import 'dart:convert';
+
 import 'package:core/presentation/extensions/color_extension.dart';
 import 'package:custom_pop_up_menu/custom_pop_up_menu.dart';
 import 'package:core/utils/app_logger.dart';
+import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
 import 'package:get/get.dart';
 import 'package:html_editor_enhanced/html_editor.dart';
@@ -257,6 +260,17 @@ class RichTextWebController extends BaseRichTextController {
     menuOrderListController.hideMenu();
   }
 
+  void insertImageAsBase64({required PlatformFile platformFile}) {
+    if (platformFile.bytes != null) {
+      final base64Data = base64Encode(platformFile.bytes!);
+      editorController.insertHtml(
+        '<img src="data:image/${platformFile.extension};base64,$base64Data" data-filename="${platformFile.name}" alt="Image in my signature" style="max-width: 100%"/>'
+      );
+    } else {
+      logError("RichTextWebController::insertImageAsBase64: bytes is null");
+    }
+  }
+
   @override
   void onClose() {
     menuParagraphController.dispose();