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]/expenses/create/page.tsx

@@ -1,27 +0,0 @@
-import { ExpenseForm } from '@/components/expense-form'
-import { createExpense, getGroup } from '@/lib/api'
-import { expenseFormSchema } from '@/lib/schemas'
-import { Metadata } from 'next'
-import { notFound, redirect } from 'next/navigation'
-
-export const metadata: Metadata = {
-  title: 'Create expense',
-}
-
-export default async function ExpensePage({
-  params: { groupId },
-}: {
-  params: { groupId: string }
-}) {
-  const group = await getGroup(groupId)
-  if (!group) notFound()
-
-  async function createExpenseAction(values: unknown) {
-    'use server'
-    const expenseFormValues = expenseFormSchema.parse(values)
-    await createExpense(expenseFormValues, groupId)
-    redirect(`/groups/${groupId}`)
-  }
-
-  return <ExpenseForm group={group} onSubmit={createExpenseAction} />
-}