refactor: unify evalClanService with evalService

lib/modules/inventory/distributed-service/resolveModule.nix

@@ -0,0 +1,43 @@
+{ lib }:
+{
+  moduleSpec,
+  flakeInputs,
+  localModuleSet,
+}:
+let
+  resolvedModuleSet =
+    # If the module.name is self then take the modules defined in the flake
+    # Otherwise its an external input which provides the modules via 'clan.modules' attribute
+    if moduleSpec.input == null then
+      localModuleSet
+    else
+      let
+        input =
+          flakeInputs.${moduleSpec.input} or (throw ''
+            Flake doesn't provide input with name '${moduleSpec.input}'
+
+            Choose one of the following inputs:
+            - ${
+              builtins.concatStringsSep "\n- " (
+                lib.attrNames (lib.filterAttrs (_name: input: input ? clan) flakeInputs)
+              )
+            }
+
+            To import a local module from 'clan.modules' remove the 'input' attribute from the module definition
+            Remove the following line from the module definition:
+
+            ...
+            - module.input = "${moduleSpec.input}"
+
+          '');
+        clanAttrs =
+          input.clan
+            or (throw "It seems the flake input ${moduleSpec.input} doesn't export any clan resources");
+      in
+      clanAttrs.modules;
+
+  resolvedModule =
+    resolvedModuleSet.${moduleSpec.name}
+      or (throw "flake doesn't provide clan-module with name ${moduleSpec.name}");
+in
+resolvedModule