Add Yii2 date conversion to admin panel

[meysampg]

Description

This merge request add ability of automatic date converting, based on Yii::t function and php-intl extension to module. If this extension is installed in server and user had been selected a language expect en on config.php file, localized date will be shown. Also Farsi translation will add to project with this merge request.

PS. I think '{0, date, MMMM dd, YYYY HH:mm:ss}' => '{0, date, dd MMMM YYYY، HH:mm:ss}', (Based on correct regional format) must be added to all translation files for correct showing of date.

Example

Without this lines

$config = [
    'id' => 'basic',
    // Some code go here
    'sourceLanguage' => 'en-US',
    'language' => 'fa-IR',
    // Some code go here

on web/config.php date is like this:

and with them is like this:

which is a correct Jalali date.

[amnah]

I added the translation file but left out the {0, date, MMMM dd, YYYY HH:mm:ss}. That part is kinda confusing and is just a template that most people would probably overwrite anyway.

Thanks! b32c7ea