Add timezone() Support to Laravel Trend for Custom Timezone Aggregations

[rtraselbd]

This update introduces the timezone() method to Laravel Trend, allowing users to specify a custom timezone for date aggregation operations. By setting a timezone, all date-based intervals (perMinute(), perDay(), etc.) are adjusted to the specified region, providing accurate data trends for specific time zones. This addition is especially beneficial for applications where data trends need to be localized, such as setting the timezone to "Asia/Dhaka" for users in Bangladesh.

Example usage:

Trend::model(Order::class)
    ->timezone('Asia/Dhaka')
    ->between(...)
    ->perDay()
    ->count();