[5.4] Improve Queue's InvalidPayloadException error message

[timacdonald]

Currently the queue can throw an InvalidPayloadException with just the last_json_error() number in the message.

I had to jump into the Queue source to understand what was actually the issue happening here. I thought perhaps we could simply give a little more context to the error. The message itself may not be exactly what should be in there - suggestions welcomed - but I think it would be good to present more info. The suggested message is:

Maybe this is more obvious to more experienced dev's then myself and isn't needed.

[lucasmichot]

Why not just setting the default in \Illuminate\Queue\InvalidPayloadException::__construct instead?

[timacdonald]

I considered that also, and the exception is only used in the one place at the moment. Just wasn't sure if that is a suitable default error message for that exception or not - as the exception is not specifically a JSON error exception. But I guess that can just be changed in the future if a non-json related error occurs that throws this exception.

[BrandonSurowiec]

Would it be more informative to use 'json_last_error_msg() instead of, or in addition to the error code?