Be able to skip caching when using fallback DNS

[Potat0000]

Prerequisites

• [X] I have checked the Wiki and 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

Right now, no matter where the DNS response gets, it will be cached (if enabled) by AdGuard Home. I wonder whether it's possible to not record the response from fallback DNS to the cache.

Proposed solution

Maybe add an option to skip caching when using fallback DNS.

Alternatives considered and additional information

No response