refactor utils

src/utils/misc.ts

@@ -0,0 +1,11 @@
+export function buildISODate(date: string, time: string | null): string {
+  return new Date(date + 'T' + time || '00:00').toISOString();
+}
+
+export function getNewId(): string {
+  return [...Array(20)]
+    .map(() => Math.floor(Math.random() * 16).toString(16))
+    .join('');
+  // Trivial placeholder
+  //return Math.max(...reservations.value.map((item) => item.id)) + 1;
+}