IP's(subnets) support in ipset file

### 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

Subnets/IPS are treated like domains

### Proposed solution

It would be great if the ipset file could support IP subnets as well.

I know this isn't strictly a DNS-related feature, but having a single file containing both domains and IP addresses for routing would be much more convenient than managing multiple files and separate ipset lists.

Implementing this should be fairly straightforward: subnets could simply be detected and added to the ipset directly, without any DNS resolution.

### Alternatives considered and additional information

_No response_