Change public IP address SKU from basic to standard

[craddm]

✅ Checklist

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🚦 Depends on

n/a

⤴️ Summary

Changes public IP address for VPN gateway from the basic SKU to standard SKU, as azure no longer allows basic SKU to be used with non-Azure VPN gateways.

🌂 Related issues

Closes #1947

🔬 Tests

Deployed locally

[jemrobinson]

LGTM

[JimMadge]

@craddm Can you update the v4.2.2 release information?