This commit moves the exception classes that SQL uses to follow the
Elasticsearch convention. In the places where varargs were used, the
`LoggerMessageFormat` (`{}`) standard is used instead.
In also removes on Exception - `ExecutionException` since it seemed to not ever
be beefed up, it can be re-added later if needed.
This removes the varargs version of `ClientException` to push the formatting
back on the caller, since `ClientException` cannot depend on Elasticsearch for
formatting the arguments.
There were also a couple of places where we incorrectly passed the Throwable
cause as a var-arg and were unintentionally swallowing it since `String.format`
discards unused arguments.
Relates to elastic/x-pack-elasticsearch#2880
Original commit: elastic/x-pack-elasticsearch@5f5d580e57
