HPCC-11148 Fix WsEcl JSONTest formatting of int64 values

Also fix escaping of json embedded in javascript.  The current request
is embedded in javascript for processing but the whole message needed to
be escaped to properly handle special characters.

Signed-off-by: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>
Merge pull request #5667 from afishbeck/jsonTestInt64Formatting3

HPCC-11148 Fix WsEcl JSONTest formatting of int64 values

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>