aquatic_ws_protocol: refactor, moving code into submodules

aquatic_ws_protocol/src/response/announce.rs

@@ -0,0 +1,14 @@
+use serde::{Deserialize, Serialize};
+
+use crate::common::*;
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct AnnounceResponse {
+    pub action: AnnounceAction,
+    pub info_hash: InfoHash,
+    /// Client checks if this is null, not clear why
+    pub complete: usize,
+    pub incomplete: usize,
+    #[serde(rename = "interval")]
+    pub announce_interval: usize, // Default 2 min probably
+}