HPCC-11167 Add Choropleth example to ECL Playground

Converted json files to js objects.
Separated States and Counties into different files.

Fixes HPCC-11167

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #5645 from GordonSmith/HPCC-11167

HPCC-11167 Add Choropleth example to ECL Playground

Reviewed-By: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>