MaxMessageSize actually limits frame size

[lukebakken]

Describe the bug

PR #1220's intent is to prevent large allocations due to bad incoming data, or large messages. The fix checks that the individual frame's size does not exceed the maximum message size, but it does not take into account the case where a large message is split into multiple frames. When combined, the message body may exceed the max message size.

Related to rabbitmq/rabbitmq-java-client#1062

Reproduction steps

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Expected behavior

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Additional context

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