HPCC-10034 Move all JSON validation and pretty printing to client side

Disable or remove JSON pretty printing in roxie and WsECL for
efficiency over the wire.

Rewrite the WsECL JSON test page to use dojo to do AJAX calls
and handle html events.  Add client side JSON validation and pretty
printing.

Signed-off-by: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>
Merge pull request #4936 from afishbeck/json_formatting

HPCC-10034 Move all JSON validation and pretty printing to client side

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>