Include the static routing defined in Virtual Networks into the VM context configuration

[chaoyi888]

Description
Brief description of the new functionality
While defining a Virtual Network, we can already define static routing under the part of Custom Attributes. But this way of defining static routing isn't included in the VM context configuration. Of course, we can also define static routing in the context of VM template, but it would alos be logical if the static routing defined in the Virtual Network will also be effective.

Use case
How are you going to use this new feature? Why do you need it?
While attaching new NICs to the VM, the VM will get the pre-defined static routing from the Virtual Networks configuration.

Interface Changes
Describe any changes you'd like to see to current interfaces including Sunstone, CLI, or/and API
In the Sunstone or CLI while defining a new Virtual Network, the Custom Attributes should also be included into the VM context configuration.

Additional Context
Please feel free to add any other context or screenshots about the feature request here. Or any other alternative you have considered to address this new feature.

Progress Status

• Code committed
• Testing - QA
• Documentation (Release notes - resolved issues, compatibility, known issues)