Change QuicCryptoStream to track crypto-substreams by packet number space instead of encryption level such that ZERO_RTT and FORWARD_SECURE crypto data are sent/received/re-transmitted on the same stream.

PiperOrigin-RevId: 447566612
diff --git a/quiche/quic/core/tls_client_handshaker.h b/quiche/quic/core/tls_client_handshaker.h
index 21b6033..06581b5 100644
--- a/quiche/quic/core/tls_client_handshaker.h
+++ b/quiche/quic/core/tls_client_handshaker.h
@@ -56,6 +56,8 @@
   bool encryption_established() const override;
   bool IsCryptoFrameExpectedForEncryptionLevel(
       EncryptionLevel level) const override;
+  EncryptionLevel GetEncryptionLevelToSendCryptoDataOfSpace(
+      PacketNumberSpace space) const override;
   bool one_rtt_keys_available() const override;
   const QuicCryptoNegotiatedParameters& crypto_negotiated_params()
       const override;