Use modal dialogs for expense creation & edition (#10)

* First attemps at using route interception and modals

* Remove route interception

* Make it work

* Use Vaul on small screens

* Improve vaul

src/app/groups/[groupId]/reimbursement-list.tsx

@@ -37,6 +37,7 @@ export function ReimbursementList({
             <Button variant="link" asChild className="-mx-4 -my-3">
               <Link
                 href={`/groups/${groupId}/expenses/create?reimbursement=yes&from=${reimbursement.from}&to=${reimbursement.to}&amount=${reimbursement.amount}`}
+                scroll={false}
               >
                 Mark as paid
               </Link>