Scheduled internet access control in AdGuard DNS

### Issue Details

Currently, internet connections can only be blocked by manually enabling a user rule, which can be inconvenient if this needs to be done daily.

### Proposed solution

Introduce the ability to set rules or schedules that automatically allow or block internet connections based on specified timeframes. For example, users could schedule internet access to be allowed only during work hours, such as 08:00-16:00

### Alternative solution

_No response_