fix: verify view is inaccessible (#8557)

Fixes https://github.com/payloadcms/payload/issues/8470

Cleans up the way we redirect and where it happens.

## Improvements
- When you verify, the admin panel will display a toast when it
redirects you to the login route. This is contextually helpful as to
what is happening.
- Removes dead code path, as we always set the _verifiedToken to null
after it is used.

## `handleAdminPage` renamed to `getRouteInfo`
This function no longer handles routing. It kicks that responsibility
back up to the initPage function.

## `isAdminAuthRoute` renamed to `isPublicAdminRoute`
This was inversely named as it determines if a given route is public.
Also simplifies deterministic logic here.

## `redirectUnauthenticatedUser` argument
This is no longer used or needed. We can determine these things by using
the `isPublicAdminRoute` function.

## View Style fixes
- Reset Password
- Forgot Password
- Unauthorized

test/access-control/e2e.spec.ts

@@ -482,7 +482,7 @@ describe('access control', () => {
         serverURL,
       })
 
-      await expect(page.locator('.next-error-h1')).toBeVisible()
+      await expect(page.locator('.unauthorized')).toBeVisible()
 
       await page.goto(logoutURL)
       await page.waitForURL(logoutURL)
@@ -500,6 +500,7 @@ describe('access control', () => {
 
     test('should block admin access to non-admin user', async () => {
       const adminURL = `${serverURL}/admin`
+      const unauthorizedURL = `${serverURL}/admin/unauthorized`
       await page.goto(adminURL)
       await page.waitForURL(adminURL)
 
@@ -527,9 +528,9 @@ describe('access control', () => {
       ])
 
       await page.goto(adminURL)
-      await page.waitForURL(adminURL)
+      await page.waitForURL(unauthorizedURL)
 
-      await expect(page.locator('.next-error-h1')).toBeVisible()
+      await expect(page.locator('.unauthorized')).toBeVisible()
     })
   })