Add ancestor rank_level to GET/observations response (API)

Feature Requests
17

this might be another way to work around the issue (written in Python) without doing any extra requests: https://forum.inaturalist.org/t/inaturalist-api-with-python-get-family-name-from-observations/53672/4

… and here’s a Javascript function adapted from the above which will return ancestors for a given observation (implemented in https://jumear.github.io/stirfry/iNatAPIv1_observations):

function fObsTaxonAncestors(obs) {
   let ancestors = [];
   let rankLevel_kingdom = 70 // this is the highest-level taxon stored in identification[i].ancestors
   let rt, taxonId, rankLevel;
   if ((rt = obs?.taxon) && (taxonId = rt?.id) && ((rankLevel = rt?.rank_level) < rankLevel_kingdom)) {
      for (let id of obs.identifications) {
         let idt, idta;
         if (idt = id?.taxon) {
            if (idt.id === taxonId) {
               ancestors = idt.ancestors;
               break;
            };
            if (idta = idt.ancestors) {
               for (let [i, atid] of idta.map((a)=>a.id).entries()) {
                  if (atid === taxonId) {
                     ancestors = idta.slice(0,i); // add everything above this taxon (will add this taxon later below)
                     break;
                  };
               };
            };
            if (ancestors?.length) { break; };
         };
      };
   };
   if (rt && rankLevel <= rankLevel_kingdom) {
      ancestors.push(rt); // add self taxon
      return ancestors;
   };
};