Delete unused files and todo comments

Author: dacharyc

mflix/server/java-spring/src/main/java/com/mongodb/samplemflix/exception/ValidationException.java

@@ -4,8 +4,7 @@
  * Exception thrown when request validation fails.
  * 
  * This exception results in a 400 Bad Request response.
- * 
- * TODO: Phase 7 - Implement custom exception
+ *
  */
 public class ValidationException extends RuntimeException {
 

mflix/server/java-spring/src/main/java/com/mongodb/samplemflix/model/Comment.java

@@ -712,8 +712,6 @@ public List<Movie> searchMovies(MovieSearchRequest searchRequest) {
         }
     }
 
-
-    // TODO: Implement vector search
     @Override
     public List<Movie> findSimilarMovies(String movieId, Integer limit) {
         // Validate movie ID