Increasing MIN-MAX-FRAME-SIZE for SASL AMQPCBS

As defined in Section 5.31 of [AMQP]:

The maximum size of a SASL frame is defined by MIN-MAX-FRAME-SIZE. There is no mechanism within the SASL negotiation to negotiate a different size.

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Due to the requirement to transfer potentially large sets of tokens during the SASL exchange, Rob Godfrey suggested that implementations of the AMQPCBS mechanisms could support a larger maximum SASL frame size.

It would be useful to have concrete information about the size of the expected token sets.