Custom filtering rules not working with ipv6 addresses

### Prerequisites

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

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

- [x] I want to report a bug and not [ask a question or ask for help](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a)

- [x] I have set up AdGuard Home correctly and [configured clients to use it](https://github.com/AdguardTeam/AdGuardHome/wiki/Clients). (Use the [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a) for help with installing and configuring clients.)

### Platform (OS and CPU architecture)

FreeBSD, AMD64 (aka x86_64)

### Installation

Custom package (OpenWrt, HomeAssistant, etc; please mention in the description)

### Setup

On a router, DHCP is handled by the router

### AdGuard Home version

v0.107.60

### Action

I'm trying to setup a custom filtering rule to allow a domain for a specific client based on the client's ipv6 address.
I tried below two rules to achieve the same result (the ipv6 address listed below is not the real ipv6 address for privacy reasons):

```
@@||g.doubleclick.net^$client=fe80::198f:2d1f:6502:7fb5
@@||g.doubleclick.net^$client='iPhone'
```

For the second rule I have first created a persistent client on the “Settings → Client settings” page using it's ipv6 address as an identifier:


And while the filter test of AGH shows the first filter rule as working correctly (filter test does not currently support testing the second rule because it uses client names):


### Expected result

The domain and it's subdomains should be allowed for that specific client.

### Actual result

The DNS requests for the domain and subdomains are still being blocked by the configured blocklist:


So both rules do not seem to work as expected.

### Additional information and/or screenshots

When leaving the client modifier out of the custom filtering rules or when using an ipv4 address, the rules do work as expected.
The issue might be related to [this issue,](https://github.com/AdguardTeam/AdGuardHome/issues/7663) but because i'm not 100% sure I created a new issue.