Add automatic generation of favourite buttons

favourite buttons are based on how often a good i added to list
finished implementing setting category
made number of days until button an environment variable

rebase on main and fix

ran cargo fmt

gui/ui/state.slint

@@ -4,6 +4,11 @@ export struct SItem {
     amount: int,
 }
 
+export struct SButtonItem{
+    name: string,
+    category: string,
+}
+
 export enum ConnectionStatus {
     Idle,
     Syncing,
@@ -22,7 +27,13 @@ export global State {
     callback delete-checked();
     callback inc-amount(string);
     callback dec-amount(string);
+    callback set-cat(string, string);
     in-out property <string> server-address;
+    in property <[SButtonItem]> favorites: [
+        { name: "mjölk", category: "kyl" },
+        { name: "ost", category: "kyl" },
+    ];
+
     callback set-server-address(string);
     set-server-address(address) => {
         server-address = address;