Add proxied autocomplete for Stadia

This allows me to make the format consistent and to cache the
intermediate results, which is useful for speed and testing

platform/geocode/autocomplete.go

@@ -0,0 +1,38 @@
+package geocode
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/Gleipnir-Technology/nidus-sync/db/models"
+	"github.com/Gleipnir-Technology/nidus-sync/stadia"
+	"github.com/rs/zerolog/log"
+)
+
+type AutocompleteResult struct {
+	Detail   string
+	Locality string
+}
+
+func Autocomplete(ctx context.Context, org *models.Organization, address string) ([]*AutocompleteResult, error) {
+	req := stadia.RequestGeocodeAutocomplete{
+		Text: address,
+	}
+	maybeAddServiceArea(&req, org)
+	resp, err := client.GeocodeAutocomplete(ctx, req)
+	if err != nil {
+		return nil, fmt.Errorf("client raw geocode failure on %s: %w", address, err)
+	}
+	result := make([]*AutocompleteResult, len(resp.Features))
+	for i, r := range resp.Features {
+		if r.Type != "Feature" {
+			log.Error().Str("type", r.Type).Msg("should be handled from Stadia")
+			continue
+		}
+		result[i] = &AutocompleteResult{
+			Detail:   r.Properties.Name,
+			Locality: r.Properties.Locality,
+		}
+	}
+	return result, nil
+}

platform/geocode/geocode.go

@@ -267,6 +267,9 @@ func allFeaturesIdenticalEnough(features []stadia.GeocodeFeature) bool {
 	return true
 }
 func maybeAddServiceArea(req stadia.RequestGeocode, org *models.Organization) {
+	if org == nil {
+		return
+	}
 	if org.ServiceAreaXmax.IsNull() ||
 		org.ServiceAreaYmax.IsNull() ||
 		org.ServiceAreaXmin.IsNull() ||