Ingest ExternalReviews from K+

Adds a new entity ExternalChapterMetadata, which would allow us to
extend chapters to Recommendations, Ratings, etc in the future

API/DTOs/SeriesDetail/UpdateUserReviewDto.cs

@@ -1,5 +1,4 @@
-using System.ComponentModel.DataAnnotations;
-
+
 namespace API.DTOs.SeriesDetail;
 #nullable enable
 
@@ -7,6 +6,5 @@ public class UpdateUserReviewDto
 {
     public int SeriesId { get; set; }
     public int? ChapterId { get; set; }
-    public int Rating { get; set; }
     public string Body { get; set; }
 }