MINOR: quic: Add a new definition to store STREAM frames.

Add a new structure to store enough information about STREAM frames which
must be stored before being delivered to the application layer, for any
reason.
diff --git a/include/haproxy/xprt_quic-t.h b/include/haproxy/xprt_quic-t.h
index d55c36b..368b5cb 100644
--- a/include/haproxy/xprt_quic-t.h
+++ b/include/haproxy/xprt_quic-t.h
@@ -445,6 +445,14 @@
 	struct quic_rx_packet *pkt;
 };
 
+/* Structure to store information about RX STREAM frames. */
+struct quic_rx_strm_frm {
+	struct eb64_node offset_node;
+	uint64_t len;
+	const unsigned char *data;
+	struct quic_rx_packet *pkt;
+};
+
 /* Flag a sent packet as being an ack-eliciting packet. */
 #define QUIC_FL_TX_PACKET_ACK_ELICITING (1UL << 0)
 /* Flag a sent packet as containing a PADDING frame. */