client/web: add copyable components throughout UI

Updates the IP address on home view to open a copyable list of node
addresses on click. And makes various values on the details view
copyable text items, mirroring the machine admin panel table.

As part of these changes, pulls the AddressCard, NiceIP and QuickCopy
components from the admin panel, with the AddressCard slightly modified
to avoid needing to also pull in the CommandLine component.

A new toaster interface is also added, allowing us to display success
and failure toasts throughout the UI. The toaster code is slightly
modified from it's admin form to avoid the need for some excess
libraries.

Updates #10261

Signed-off-by: Sonia Appasamy <sonia@tailscale.com>

client/web/src/utils/util.ts

@@ -0,0 +1,44 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+/**
+ * assertNever ensures a branch of code can never be reached,
+ * resulting in a Typescript error if it can.
+ */
+export function assertNever(a: never): never {
+  return a
+}
+
+/**
+ * noop is an empty function for use as a default value.
+ */
+export function noop() {}
+
+/**
+ * pluralize is a very simple function that returns either
+ * the singular or plural form of a string based on the given
+ * quantity.
+ *
+ * TODO: Ideally this would use a localized pluralization.
+ */
+export function pluralize(signular: string, plural: string, qty: number) {
+  return qty === 1 ? signular : plural
+}
+
+/**
+ * isTailscaleIPv6 returns true when the ip matches
+ * Tailnet's IPv6 format.
+ */
+export function isTailscaleIPv6(ip: string): boolean {
+  return ip.startsWith("fd7a:115c:a1e0")
+}
+
+/**
+ * isPromise returns whether the current value is a promise.
+ */
+export function isPromise<T = unknown>(val: unknown): val is Promise<T> {
+  if (!val) {
+    return false
+  }
+  return typeof val === "object" && "then" in val
+}