Remove duplicate code for `TorrentPeerBuilder`

There is a `TorrentPeerBuilder` at least in three different modules:

- packages/torrent-repository-benchmarking/tests/common/torrent_peer_builder.rs
- packages/udp-tracker-server/src/handlers/mod.rs

```rust
#[derive(Debug, Default)]
pub struct TorrentPeerBuilder {
    peer: peer::Peer,
}
```

We can move it to the `torrust_tracker_primitives` package, where the `Peer` is located.