Multiple wifis - no multiple domains

**Describe the problem you have/What new integration you would like**
Hi all,

I actually expect a support of multiple domains when using multiple wifis. It's not uncommon that different networks use different domains.
```
wifi:
networks:
- ssid: !secret wifi_1_ssid
password: !secret wifi_1_password
# domain: ".domain1"
- ssid: !secret wifi_2_ssid
password: !secret wifi_2_password
# domain: ".domain2"
```

Although I'm unsure if this is possible anyway because the hostname is set generally and not network specific...?

**Please describe your use case for this integration and alternatives you've tried:**
There's actually no alternative, I can't make it happen.

**Additional context**

Start by tracing how the configured WiFi networks and the generally set hostname are handled, focusing on whether domain settings can be scoped to each network. Done means documenting or implementing a supported per-network domain configuration and confirming that switching between the listed networks uses the corresponding domain.

Written by the indexing model from the issue text.