TF-1961 Left align signature and title header reply/forward email

(cherry picked from commit 9ec81d062d945076d80f4eb4d0cc4e792514cb79)

core/lib/presentation/extensions/html_extension.dart

@@ -35,4 +35,9 @@ extension HtmlExtension on String {
     }
     return this;
   }
+
+  String addCiteTag() => addBlockTag(
+    'cite',
+    attribute: 'style="text-align: left;display: block;"'
+  );
 }

core/lib/presentation/utils/html_transformer/html_utils.dart

@@ -75,7 +75,7 @@ class HtmlUtils {
       const options = {
         root: null, // Use the viewport as the root
         rootMargin: "0px",
-        threshold: 0.1 // Specify the threshold for intersection
+        threshold: 0 // Specify the threshold for intersection
       };
       
       const handleIntersection = (entries, observer) => {
@@ -131,6 +131,10 @@ class HtmlUtils {
             border-radius: 4px;
             overflow: auto;
           }
+          
+          div.tmail-signature {
+            text-align: left;
+          }
         </style>
       ''';
     } else if (PlatformInfo.isMobile) {
@@ -138,6 +142,10 @@ class HtmlUtils {
         #editor {
           direction: ${direction.name};
         }
+        
+        div.tmail-signature {
+          text-align: left;
+        }
       ''';
     } else {
       return '';