feat(printer): 添加sourceId字段并优化打印逻辑

- 在MemberPrintResp中新增sourceId字段
- 优化PrinterServiceImpl中的水印处理逻辑
- 添加sourceId为空时的返回判断，避免空指针异常

src/main/java/com/ycwl/basic/model/pc/printer/resp/MemberPrintResp.java

@@ -8,6 +8,7 @@ import java.util.Date;
 public class MemberPrintResp {
     private Integer id;
     private Long scenicId;
+    private Long sourceId;
     private String scenicName;
     private Long faceId;
     private Long memberId;