Management Server does not recognize a session as removed in some scenarios

### Problem Description

In some scenarios, the Management Server does not recognize that a console session has been released. As a consequence of that, the `removed` column of the `cloud.console_session` table remains indefinitely marked as `NULL`.

### Versions

ACS versions 4.19 and 4.20

### The steps to reproduce the bug

- https://github.com/apache/cloudstack/pull/11016#pullrequestreview-2993780512 and https://github.com/apache/cloudstack/pull/11016#issuecomment-3052399701 describe two different situations in which this bug occur.

### What to do about it?

Normalize these scenarios, ensuring that the `removed` attribute of console sessions is corretly set to the datetime in which the sessions are released.

まず、pull request #11016 の review とコメントで説明されている 2 つのシナリオを読み、次に Management Server が console-session の解放イベントをどのように記録しているかを追跡します。cloud.console_session テーブルに対して動作を検証し、報告された各シナリオで removed が NULL のままではなく解放日時に設定されれば、作業完了とします。

索引モデルが issue の本文から書いたものです。