Fetch a USAJobs reference codelist (lookup tables behind every federal job posting). Pass name to pick which list: agencysubelements (every agency + sub-element), occupationalseries (2210 IT, 0301 Misc Admin, 0801 Engineer, etc.), paygrades, payplans (GS, SES, ES, WG, etc.), hiringpaths (veteran, military spouse, native American, etc.), securityclearances, locationcodes, countries, countrysubdivisions, ethnicities, racecodes, militarystatuscodes, languagecodes, positionscheduletypecodes (full-time/part-time/seasonal), travelpercentages, missioncriticalcodes, cyberworkroles, etc. (33 lists total). Use the returned codes as filter inputs to /api/job/federal-search.