feat: New CloudWAN and Transit Gateway subnets

[wiseelf]

Description

Added two additional subnets for Transit Gateway and CloudWAN.

Motivation and Context

In order to follow AWS best practices for CloudWAN and Transit Gateway there is a need in two additional subnets for each. Example of documentation: https://docs.aws.amazon.com/vpc/latest/tgw/tgw-best-design-practices.html

Use a separate subnet for each transit gateway VPC attachment. For each subnet, use a small CIDR, for example /28, so that you have more addresses for EC2 resources. When you use a separate subnet, you can configure the following:

1. Keep the inbound and outbound network ACLs associated with the transit gateway subnets open.
2. Depending on your traffic flow, you can apply network ACLs to your workload subnets.

Breaking Changes

No breaking changes

How Has This Been Tested?

• I have updated at least one of the examples/* to demonstrate and validate my change(s)
• I have tested and validated these changes using one or more of the provided examples/* projects
• I have executed pre-commit run -a on my pull request

[wiseelf]

@antonbabenko @bryantbiggs sorry for the mention, but please review, not sure how to assign reviewers here.

[sknmi]

We would like to have this as well. Also this fixes: #888

[sknmi]

@antonbabenko @bryantbiggs could you guys have a look at this and get this merged?

[antonbabenko]

This is not something we would like to get implemented in the current version of the module because technically, these new types of subnets are the same as the available types (probably, private). We will have possibility to manage such resources in the next major release of this module. Closing for now.

[wiseelf]

@antonbabenko they are basically internal. The main idea is to have separate ACL attached to them. It is not a breaking change or something, so why you so against of implementing this?

[antonbabenko]

Right, internal. Maintenance cost is the main reason for not adding "just one more resource" to this module but rather refactoring it smarter.

[github-actions]

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