TF-3035 Restore identity from draft

lib/features/mailbox_dashboard/data/model/composer_cache.dart

@@ -1,5 +1,4 @@
 import 'package:equatable/equatable.dart';
-import 'package:jmap_dart_client/jmap/identities/identity.dart';
 import 'package:jmap_dart_client/jmap/mail/email/email.dart';
 import 'package:json_annotation/json_annotation.dart';
 import 'package:tmail_ui_user/features/composer/presentation/model/screen_display_mode.dart';
@@ -10,13 +9,11 @@ part 'composer_cache.g.dart';
 class ComposerCache with EquatableMixin {
 
   final Email? email;
-  final Identity? identity;
   final bool? hasRequestReadReceipt;
   final ScreenDisplayMode displayMode;
 
   ComposerCache({
     this.email,
-    this.identity,
     this.hasRequestReadReceipt,
     this.displayMode = ScreenDisplayMode.normal
   });
@@ -28,7 +25,6 @@ class ComposerCache with EquatableMixin {
   @override
   List<Object?> get props => [
     email,
-    identity,
     hasRequestReadReceipt,
     displayMode
   ];