Ability to override http_proxy/https_proxy to reach Vault

[mikeyyuen]

I work in an enterprise where different multiple http proxies are involved in connecting to different services. Specifically one proxy for accessing the internet and one for accessing security resources like HashiCorp Vault. Could the Vault Provider be enhanced to allow us to override the http_proxy/https_proxy it uses?

I imagine this could be passed in through the provider config (but this is just a suggestion)

provider "vault" {
  address = "https://vault.example.net:8200"
  proxy = "http://internetproxy.corpdomain.com:80"
}

In a complex network enviornment, this would allow the terraform provider to be used along side the aws/gcp/azure providers.