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.

从链接的讨论和 security_group.py 脚本开始，以了解所请求的行为和当前的流量处理方式。定义配置选项应如何在 Basic Networking 中允许嵌套 VM 流量而不修改脚本，然后验证该选项是否适用于所描述的 CloudStack 设置。

由索引模型根据 Issue 内容生成。