Implement terraform code to provision Vertex AI resources

[damondouglas]

This PR closes #27978 by implementing terraform to provision Vertex AI resources. It relies on a nested terraform map object variable and for each syntax to simplify configuration. Additionally, there is a synthea.tfvars of an example configuration.

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R: @AnandInguva added as fallback since no labels match configuration

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[github-actions]

Reminder, please take a look at this pr: @AnandInguva

[AnandInguva]

I am not an expert here but this LGTM