feat(aria2): show detailed error message from aria2 (#2296)

pkg/downloader/aria2/aria2.go

@@ -139,6 +139,7 @@ func (a *aria2Client) Info(ctx context.Context, handle *downloader.TaskHandle) (
 		UploadSpeed:   uploadSpeed,
 		SavePath:      savePath,
 		NumPieces:     numPieces,
+		ErrorMessage:  status.ErrorMessage,
 		Hash:          status.InfoHash,
 		Files: lo.Map(status.Files, func(item rpc.FileInfo, index int) downloader.TaskFile {
 			index, _ = strconv.Atoi(item.Index)

pkg/downloader/downloader.go

@@ -44,6 +44,7 @@ type (
 		Files         []TaskFile  `json:"files,omitempty"`
 		Pieces        []byte      `json:"pieces,omitempty"` // Hexadecimal representation of the download progress of the peer. The highest bit corresponds to the piece at index 0.
 		NumPieces     int         `json:"num_pieces,omitempty"`
+		ErrorMessage  string      `json:"error_message,omitempty"`
 	}
 
 	TaskFile struct {