Add custom impermanence module

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/user/configs/gui/qalculate/default.nix

@@ -1,5 +1,6 @@
 {
-  username ? throw "username argument is required",
+  user ? throw "user argument is required",
+  home ? throw "home argument is required",
 }:
 {
   lib,
@@ -7,9 +8,6 @@
   pkgs,
   ...
 }:
-let
-  hmConfig = config.home-manager.users.${username};
-in
 {
   nixpkgs.overlays = [
     (final: prev: {
@@ -19,11 +17,9 @@ in
     })
   ];
 
-  environment.persistence."/cache".users.${username}.files = [
-    "${hmConfig.xdg.relativeConfigHome}/qalculate/qalculate-gtk.history"
-  ];
+  environment.persistence."/cache"."${home}/.config/qalculate/qalculate-gtk.history" = { };
 
-  home-manager.users.${username} = {
+  home-manager.users.${user} = {
     home.packages = with pkgs; [ qalculate-gtk ];
 
     xdg.configFile."qalculate/qalculate-gtk.cfg".source =