An Config option to simply allow nested VM access

### The required feature described as a wish

As asked in this discusssion: https://github.com/apache/cloudstack/discussions/10225

I would like to have an easier way to allow network traffic to nested VM's in basic networking installations.

Currently you would need to manually "hack" the `security_group.py` script to just not execute anything at all.
This would be useful for inhouse non security sensitive installation where people could simply host e.g. test CloudStack installations
or other virtualization platforms to test.

從連結的討論和 security_group.py 指令碼開始，以了解所要求的行為和目前的流量處理方式。定義設定選項應如何在 Basic Networking 中允許巢狀 VM 流量而不修改指令碼，然後驗證該選項是否適用於所描述的 CloudStack 設定。

由索引模型根據 Issue 內容生成。