Clean up lombok annotations in API response models

We can clean up and only annotate our API response models with the following lombok annotations: @EqualsAndHashCode and @ToString

For example:

@EqualsAndHashCode
@ToString
public final class FooResponse {
  @Getter private final String value;
  private final String description;

  public FooResponse(
      @NonNull final String value,
      @Nullable final String description) {
    this.name = checkNotBlank(value);
    this.description = description;
  }

  public Optional<String> getDescription() {
    return Optional.ofNullable(description);
  }
}

NOTE: For a great API response model example, see DatasetResponse

[ravikamaraj]

@wslulciuc , can you close this issue. thanks.

PS: with recent PR’s, I am following CONTRIBUTING.md to close the issue automatically upon PR approval

[wslulciuc]

Fixed #573