rename propolis-server-config and add spec helper

Now that config TOMLs no longer configure Propolis servers, rename
the propolis-server-config crate to propolis-config-toml, then add code
to convert a config TOML into a set of instance spec configuration
options. Most of this code already existed in propolis-server's config
TOML processor, which is now deleted.

Also tweak a couple of field names in the SoftNPU port spec type to
clarify that the name that a port has *within a SoftNPU setup* is
distinct from its instance spec component key.

Cargo.toml

@@ -49,7 +49,7 @@ cpuid_profile_config = { path = "crates/cpuid-profile-config" }
 dladm = { path = "crates/dladm" }
 nvpair = { path = "crates/nvpair" }
 nvpair_sys = { path = "crates/nvpair/sys" }
-propolis-server-config = { path = "crates/propolis-server-config" }
+propolis-config-toml = { path = "crates/propolis-config-toml" }
 propolis_api_types = { path = "crates/propolis-api-types" }
 propolis_types = { path = "crates/propolis-types" }
 rfb = { path = "crates/rfb" }

bin/propolis-server/src/lib/spec/api_spec_v0.rs

@@ -196,7 +196,7 @@ impl From<Spec> for InstanceSpecV0 {
                     &mut spec,
                     port_name.clone(),
                     ComponentV0::SoftNpuPort(SoftNpuPortSpec {
-                        name: port_name,
+                        link_name: port.link_name,
                         backend_name: port.backend_name.clone(),
                     }),
                 );
@@ -346,6 +346,7 @@ impl TryFrom<InstanceSpecV0> for Spec {
                         })?;
 
                     let port = SoftNpuPort {
+                        link_name: port.link_name,
                         backend_name: port.backend_name,
                         backend_spec,
                     };