HttpExceptionのメッセージ及び適切な例外に修正

## 概要(Overview)

EC-CUBE/ec-cube#2028 の変更に伴うメッセージおよび例外の修正

## 期待する内容(Expect) or 要望 (Requirement)

- 不適切なNotFoundHttpExceptionの見直し
- 本来NotFoundではない業務エラーでNotFoundを投げている
- メッセージをセットしているNotFoundHttpExceptionを洗い出し

Search the codebase for NotFoundHttpException usages and places where its message is set. Review each occurrence against the issue's distinction between true not-found cases and business errors, then verify that corrected exception types and messages match the expected behavior. Done means inappropriate NotFoundHttpException uses have been replaced and their messages are corrected.

Written by the indexing model from the issue text.