针对有-items参数时，视频的序号应该取整个合集中的序号，而不是取被下载的第几个 (#1317)

* bilibili playlist下载时 LUX will skip files with same names

* 下载playlist列表的时候添加  P1  P2 ... 后缀

* Update bilibili.go 针对有-items参数时，视频的序号应该取整个合集中的序号，而不是取被下载的第几个

extractors/bilibili/bilibili.go

@@ -297,7 +297,7 @@ func multiEpisodeDownload(url, html string, extractOption extractors.Options, pa
 			aid:      u.Aid,
 			bvid:     u.BVid,
 			cid:      u.Cid,
-			subtitle: fmt.Sprintf("%s P%d", u.Title, dataIndex+1),
+			subtitle: fmt.Sprintf("%s P%d", u.Title, index+1),
 		}
 		go func(index int, options bilibiliOptions, extractedData []*extractors.Data) {
 			defer wgp.Done()