Malformed newness checks for presence should result in a failed connection

[mattheworiordan]

See https://github.com/ably/ably-java/blob/159018c30b3ef813a9d3ca3c6bc82f51aacbbc68/lib/src/main/java/io/ably/lib/realtime/Presence.java#L901-L912 and https://github.com/ably/ably-dotnet/pull/157#discussion_r149350461

If we receive a presence message from Ably that is malformed, then the client can no longer guarantee integrity of that connection, but more specifically possibly just the channel.

We should not be silently failing here. Instead, we should raise an error and fail the channel with a suitable message.

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