Make it possible to put custom DNS in Quick Settings

[Banhogato]

What would you like to add or change?:
I would like to set my own DNS resolvers on quick settings, not just de primary, but fallback also, since the default ones in Portmaster aren't my preferred.

Why do you and others need this?:
People who prefer other DNS resolvers than the default and people that managed to set other options for DNS resolvers, like Unbound and AdGuard Home.
Everytime I use my VPN, that isn't a VPN that let me use my system DNS resolver, I need to remove all the DNS in the list for it work properly, and when I turn my VPN off, I have to control+C and control+V my resolvers back, because I don't use the default ones. I use Unbound.
This would be much more confortable and faster for everyone.