Make HTTP client's timeout configurable

### Prerequisites

- [X] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/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

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_