Improve error message for the case where there is too much entity data to return

[jmthibault79]

As seen at https://gatkforums.broadinstitute.org/gatk/discussion/12127/bug-getentitieswithtype-api-broken we have an unfriendly error message "sendReceive doesn't support chunked responses, try sendTo instead"

We should check for an entity response that is too large for us to handle, and respond with an error indicating that the user should use the paginated query.

Questions: what is too large? How can we detect this?