[FEATURE] Support for a SOCKS proxy

[timwisbauer-contsec]

Is your feature request related to a problem?

A SOCKS proxy is a helpful tool for interacting with OpenSearch clusters deployed into a VPC. It's a little easier to work with than a SSH tunnel and in our case we already use them for interacting with other resources. Many other providers support a SOCKS proxy as a way to connect to private clusters.

What solution would you like?

Add SOCKS proxy support to the HTTP clients used in this provider.

What alternatives have you considered?

We've considered using the SSH tunnel approach, but would need to build a SSH tunnel feature into our Terraform deployment platform so we'd prefer to leverage the existing SOCKS proxy features.

Do you have any additional context?

No