HPCC-12492 ECL Watch add indicators for keyed columns

For index results indicate which columns are part of the index
Also add indicator on the result filter.

Fixes HPCC-12492

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #6611 from GordonSmith/HPCC-12492

HPCC-12492 ECL Watch add indicators for keyed columns

Reviewed-By: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>