UDP/RFC3164: Not capturing sender IP address?

Was there a reason the UDP input for syslog doesn't store the sender's IP address?

it seems like we don't do anything with it but it could be added to the output record?

```rust
79 let (length, _src) = match socket.recv_from(&mut buf) {
80 Ok(res) => res,
81 Err(_) => continue,
82 };
```

```rust
70 #[derive(Debug)]
71 pub struct Record {
72 pub ts: f64,
73 pub hostname: String,
74 pub facility: Option,
75 pub severity: Option,
76 pub appname: Option,
77 pub procid: Option,
78 pub msgid: Option,
79 pub msg: Option,
80 pub full_msg: Option,
81 pub sd: Option>,
82 }
```

Start at the UDP input's socket.recv_from call and the Record struct shown in the issue; trace how parsed records are emitted. Determine how the sender address should be represented in the output record, then verify UDP records expose it.

Written by the indexing model from the issue text.