feat: RESTful API support update Geo file

and can set update url by user, eg.
geox-url:
  geoip: "http://xxxx/gepip.dat"
  mmdb: "http://xxxx/country.mmdb"
  geosite: "http://xxxx/geosite.dat"

config/updateGeo.go

@@ -0,0 +1,82 @@
+package config
+
+import (
+	"fmt"
+	"github.com/Dreamacro/clash/component/geodata"
+	_ "github.com/Dreamacro/clash/component/geodata/standard"
+	C "github.com/Dreamacro/clash/constant"
+	"github.com/oschwald/geoip2-golang"
+	"os"
+	"runtime"
+)
+
+func UpdateGeoDatabases() error {
+	var (
+		tmpMMDB    = C.Path.Resolve("temp_country.mmdb")
+		tmpGepIP   = C.Path.Resolve("temp_geoip.dat")
+		tmpGeoSite = C.Path.Resolve("temp_geosite.dat")
+	)
+
+	if C.GeodataMode {
+		if err := downloadGeoIP(tmpGepIP); err != nil {
+			return fmt.Errorf("can't download MMDB database file: %w", err)
+		}
+
+		if err := verifyGeoSite("temp_geoip.dat"); err != nil {
+			_ = os.Remove(tmpGepIP)
+			return fmt.Errorf("invalid GeoIP database file: %s", err)
+		}
+
+		if err := os.Rename(tmpGepIP, C.Path.GeoIP()); err != nil {
+			return fmt.Errorf("can't rename MMDB database file: %w", err)
+		}
+
+	} else {
+		if err := downloadMMDB(tmpMMDB); err != nil {
+			return fmt.Errorf("can't download MMDB database file: %w", err)
+		}
+
+		if err := verifyMMDB("temp_country.mmdb"); err != nil {
+			_ = os.Remove(tmpMMDB)
+			return fmt.Errorf("invalid MMDB database file: %s", err)
+		}
+
+		if err := os.Rename(tmpMMDB, C.Path.MMDB()); err != nil {
+			return fmt.Errorf("can't rename MMDB database file: %w", err)
+		}
+	}
+
+	if err := downloadGeoSite(tmpGeoSite); err != nil {
+		return fmt.Errorf("can't download GeoSite database file: %w", err)
+	}
+
+	if err := verifyGeoSite("temp_geosite.dat"); err != nil {
+		_ = os.Remove(tmpGeoSite)
+		return fmt.Errorf("invalid GeoSite database file: %s", err)
+	}
+
+	if err := os.Rename(tmpGeoSite, C.Path.GeoSite()); err != nil {
+		return fmt.Errorf("can't rename GeoSite database file: %w", err)
+	}
+	runtime.GC()
+	return nil
+}
+
+func verifyMMDB(path string) error {
+	instance, err := geoip2.Open(path)
+	if err == nil {
+		_ = instance.Close()
+	}
+	return err
+}
+
+func verifyGeoSite(path string) error {
+	geoLoader, err := geodata.GetGeoDataLoader("standard")
+	if err != nil {
+		return err
+	}
+
+	_, err = geoLoader.LoadSite(path, "cn")
+
+	return err
+}