A peer may emit a MAX_STREAMS frame to increase the window of opened
streams. Such frame is parsed via qcc_recv_max_streams() since 3.3 as it
is mandatory for backend support.
This patch fixes the maximum value authorized in MAX_STREAMS. As
specified by RFC 9000, it cannot exceed 2^60, the maximum number of
streams of a given type, as stream IDs are encoded on 62 bits with the 2
least significant bits reserved for the type.