feat(Users): Add count of follows and followers

src/main/java/fr/univnantes/webandcloud/api/core/User.java

@@ -91,4 +91,14 @@ public class User implements WithIdentifier {
     public List<Post> getLikedPosts() {
         return likedPosts;
     }
+
+    @Schema(description = "Number of followers of this user", example = "2")
+    public Integer getNbFollowers() {
+        return getFollowers() != null ? getFollowers().size() : null;
+    }
+
+    @Schema(description = "Number of follows of this user", example = "2")
+    public Integer getNbFollows() {
+        return getFollows() != null ? getFollows().size() : null;
+    }
 }