Make HTTP client's timeout configurable

[ainar-g]

Prerequisites

• I have checked the Wiki and Discussions and found no answer

• I have searched other issues and found no duplicates

• I want to request a feature or enhancement and not ask a question

The problem

Currently, the AdGuard Home HTTP client has a hardcoded five-minute timeout. Which is fine for most cases, but can become an issue when the i/o is known to be slow, see #7041.

Proposed solution

Make the HTTP client timeout configurable.

Alternatives considered and additional information

No response