feat: Add support for virt package

- Add sal-virt package to the workspace members
- Update MONOREPO_CONVERSION_PLAN.md to reflect the
  completion of sal-process and sal-virt packages
- Update src/lib.rs to include sal-virt
- Update src/postgresclient to use sal-virt instead of local
  virt module
- Update tests to use sal-virt

Cargo.toml

@@ -11,7 +11,7 @@ categories = ["os", "filesystem", "api-bindings"]
 readme = "README.md"
 
 [workspace]
-members = [".", "vault", "git", "redisclient", "mycelium", "text", "os", "net", "zinit_client", "process"]
+members = [".", "vault", "git", "redisclient", "mycelium", "text", "os", "net", "zinit_client", "process", "virt"]
 
 [dependencies]
 hex = "0.4"
@@ -67,6 +67,7 @@ sal-os = { path = "os" }
 sal-net = { path = "net" }
 sal-zinit-client = { path = "zinit_client" }
 sal-process = { path = "process" }
+sal-virt = { path = "virt" }
 
 # Optional features for specific OS functionality
 [target.'cfg(unix)'.dependencies]