feat: add sops-deploy module

[megheaiulian]

Summary

• Adds sops-deploy module for deploying sops-encrypted secrets to remote hosts
• Extracts secrets from sops files and transfers via SSH
• Provides id output for use as trigger in dependent resources

Usage

module "sops" {
  source   = "git::https://github.com/plumelo/nixtf.git//modules/sops-deploy"
  host     = "192.168.1.100"
  path     = "\${path.module}/secrets.yaml"
  key      = "[\"age\"][\"key\"]"
}