HPCC-11472 Choropleth does not display in ECL Playground

Only worked in IE because it fails to clip the SVG element.

Fixes HPCC-11472

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #5948 from GordonSmith/HPCC-11472

HPCC-11472 Choropleth does not display in ECL Playground

Reviewed-By: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>