GEODE-9552: Change how Radish server shutdown/disconnect is handled

[DonalEvans]

• Close client connection on CancelException
• Fix handling of RedisCommandParserException
• Remove unused constants

Authored-by: Donal Evans doevans@vmware.com

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[upthewaterspout]

I wondering why we never saw a problem with CacheClosedException, honestly. I looked at the redis source code, and I don't see that "The server is shutting down" error message sent back to a client anywhere, so I would be surprised if that was being handled correctly by clients.

[DonalEvans]

I wondering why we never saw a problem with CacheClosedException, honestly. I looked at the redis source code, and I don't see that "The server is shutting down" error message sent back to a client anywhere, so I would be surprised if that was being handled correctly by clients.

It's surprising, yeah. I wonder if it's possible we got lucky and were just never doing anything that would cause a CacheClosedException to be thrown to here.