FR: BatchResponse could return token of each message

[TupaNegreiros]

• Operating System version: Win 10 22H2
• Firebase SDK version: 2.4.0
• Firebase Product: Messaging
• .NET version: Framework 4.7

BatchResponse result = await messaging.SendMulticastAsync(message);

MulticastMessage has a List of tokens, SendMulticastAsync returns a BatchResponse with a list of message ids of succedded messages or exceptions of failed ones. BatchResponse could return the token string in each response, so we could associate each device token with success or failure.

[Naxaliav]

@TupaNegreiros there was similar issue raised a while ago and authors previously answered that the order of batchResponse matches the tokens order in request, so you can actually map that manually :) (I hope that did not change, @hiranya911 can someone confirm this?). Ofcourse having explicit token in response would be way better 🚀