feat: Add outside_ip_address_type argument to aws_vpn_connection resources

[gladavius]

Description

Add the argument outside_ip_address_type to vpn resources

Motivation and Context

Since the release of this new feature it's now possible to create a priate s2s vpn over direct connect.

This PR aim to provide this feature but keep the default value to public in order to avoid disturbance for existing connections.

A new minimal example with this feature turned on has been added.

Breaking Changes

No

How Has This Been Tested?

• [x] I have updated at least one of the examples/* to demonstrate and validate my change(s)
• [x] I have tested and validated these changes using one or more of the provided examples/* projects

• [x] I have executed pre-commit run -a on my pull request