Implement Event log / Error log in web interface

### Prerequisites

- [x] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions) and found no answer

- [x] I have searched other issues and found no duplicates

- [x] I want to request a feature or enhancement and not ask a question

### The problem

Using a Raspberry Pi, the only way to see errors is to access journalctl via command line or ssh.

### Proposed solution

Analog to Query log I would like to have a log which shows events and errors on the web interface. Ideally even with a notification badge, so that errors do not go unnoticed.

### Alternatives considered and additional information

_No response_