fix: sending a secure reply using the created draft produces a new thread issue (#2677)

Co-authored-by: Ioan Moldovan <mobilestar108@outlook.com>

Author: ioanatflowcrypt

FlowCrypt/Functionality/Mail Provider/Message Provider/Gmail+Message.swift

@@ -21,7 +21,10 @@ extension GmailService: MessageProvider {
 
         let query = createMessageQuery(identifier: identifier, format: kGTLRGmailFormatFull)
         return try await withCheckedThrowingContinuation { continuation in
-            self.gmailService.executeQuery(query) { _, data, error in
+            self.gmailService.executeQuery(query) {
+                _,
+                data,
+                error in
                 if let error {
                     return continuation.resume(throwing: GmailApiError.providerError(error))
                 }

FlowCrypt/Functionality/Mail Provider/Message Provider/Gmail+MessageExtension.swift

@@ -44,6 +44,7 @@ extension Message {
         var replyTo: String?
         var inReplyTo: String?
         var rfc822MsgId: String?
+        var replyToMsgId: String?
         var isSuspicious = false
 
         for messageHeader in messageHeaders.compactMap({ $0 }) {
@@ -58,7 +59,9 @@ extension Message {
             case .cc: cc = value
             case .bcc: bcc = value
             case .replyTo: replyTo = value
-            case .inReplyTo: inReplyTo = value
+            case .inReplyTo:
+                inReplyTo = value
+                replyToMsgId = value
             case .receivedSPF: isSuspicious = value.contains("softfail")
             case .identifier: rfc822MsgId = value
             default: break
@@ -84,6 +87,7 @@ extension Message {
             bcc: bcc,
             replyTo: replyTo,
             inReplyTo: inReplyTo,
+            replyToMsgId: replyToMsgId,
             isSuspicious: isSuspicious
         )
     }