[8.x] Allow Remember Me cookie time to be overriden

[JamesFreeman]

We want to restrict how long a remember-me token will exist for certain guards. For usual web users, we want to allow them to be logged in forever, but for staff members, we want to expire the remember me token after 30 days.

With this PR, I've made it so you can add rememberMeTokenDuration to the guard in config/auth.php. If you do not provide this, it will maintain the same cookie expiration date which is 5 years.

[bryceandy]

I've made it so you can add rememberMeTokenDuration to the guard in config/auth.php.

Since rememberMeTokenDuration is renamed to remember, is this the allowed syntax?

'guards' => [
    'web' => [
        'driver' => 'session',
        'provider' => 'users',
        'remember' => 43200,
    ],
    // ...
],

[JamesFreeman]

Hey @bryceandy, this is how I've got mine configured:

'guards' => [
     //...
     'admin' => [
            'driver' => 'session',
            'provider' => 'admin',
            'remember' => now()->addDays(30)->diffInMinutes(),
     ],
]

I'll send in a PR to docs, this evening 👍