Remove linguistic isolation fields from EJSCREEN from the backend generation of csv

[BethMattern]

Remove Percent of households in linguistic isolation from the backend generation of the CSV. That data comes from EJSCREEN and we should use the two fields we calculate directly from ACS instead.

See below for reference: Add Linguistic isolation ❌ Add Linguistic isolation (percentile) ❌

Linguistic isolation (percent) ✅ ❓ Percent of households in linguistic isolation ✅ ❓ Linguistic isolation (percent) (percentile) ✅ ❓ Percent of households in linguistic isolation (percentile) ✅ ❓

[switzersc-usds]

Related to #846