core: full deletion by sender based on preference; don't overwrite item content on "mark deleted" (#1470)

packages/simplex-chat-client/typescript/src/response.ts

@@ -266,7 +266,8 @@ export interface CRChatItemUpdated extends CR {
 export interface CRChatItemDeleted extends CR {
   type: "chatItemDeleted"
   deletedChatItem: AChatItem
-  toChatItem: AChatItem
+  toChatItem?: AChatItem
+  byUser: boolean
 }
 
 export interface CRMsgIntegrityError extends CR {