fun createBackupStoreMessage(input: InputStream, keySeed: String): Single<StoreBackupMessage>
See DotnetBackupService.createBackupStoreMessage. Creates a backup store message from a local backup result. This involves creating a key pair used for message signatures from the seed used for backup. A temporary wallet is used so that the message can be constructed multiple times if needed (e.g. error when sending). The following is done: