the ability to set User component by configuartion

[taskibayev]

Q	A
Is bugfix?	no
New feature?	yes
Breaks BC?
Tests pass?	no
Fixed issues	comma-separated list of tickets # fixed by the PR, if any

[taskibayev]

hello
probably i should open an issue before creating PR.

So why i did it (created PR)?

i'm working with CMS LUYA. and developing a account module for my project (project is not in github).

i faced some problems when tried to configurate User component in app configuration. (which could be accessed by Yii::$app->getUser())

I confugurated User component in my account module (which colud be accessed by Yii::$app->getModule('account')->getUserIdentity() )

And i used this yii2-authclient to implement social-net-work authorization.

After successfully authoration yiisoft/yii2-authclient redirects to url, which is retrived from Yii::$app->getUser(), which is app component.

But i need to retrieve url from my module user component Yii::$app->getModule('account')->getUserIdentity()

So in this PR i implemented ability to set user component by configuration.

Code would like this:
`
public function actions()

{
    return [
        'auth' => [
            'class' => 'yii\authclient\AuthAction',
            'successCallback' => [$this, 'onAuthSuccess'],
            'user' => Yii::$app->getModule('account')->getUserIdentity(),
        ],
    ];
} 

`

[samdark]

I think it should allow setting ID of the component as well as configuration array instead of user instance only i.e. https://github.com/yiisoft/yii2/blob/master/framework/BaseYii.php#L342

[taskibayev]

confused with amend commit, so 1 commit turned into 2 commits. I'm not that strong with git, totaly confused with reverting commit.
So "setting user component id instead of user instance" sets component id
and "mend" some corrections in comments

[samdark]

@lab362 please check if #230 works for you. Thanks.