Collections: allow to drag and drop to change book position

internal/dto/in.go

@@ -51,6 +51,11 @@ type CollectionBook struct {
 	BookID uint `json:"bookId" binding:"required"`
 }
 
+type CollectionItemPosition struct {
+	Position uint `json:"position" binding:"required,gte=1"`
+	ItemID   uint `json:"itemId" binding:"required"`
+}
+
 type FileInfoPost struct {
 	FileID   uint   `json:"fileId"`
 	FilePath string `json:"filepath"`