fix: 修复当base64字符串长度不为4的倍数时，解码失败的问题

update: 提高根据ISO匹配国家名称的正确率

parser/base64.go

@@ -2,9 +2,14 @@ package parser
 
 import (
 	"encoding/base64"
+	"strings"
 )
 
 func DecodeBase64(s string) (string, error) {
+	s = strings.TrimSpace(s)
+	if len(s)%4 != 0 {
+		s += strings.Repeat("=", 4-len(s)%4)
+	}
 	decodeStr, err := base64.StdEncoding.DecodeString(s)
 	if err != nil {
 		return "", err