feat(safety): implement report content API

crates/quark/src/models/safety/snapshot.rs

@@ -0,0 +1,25 @@
+use serde::{Deserialize, Serialize};
+
+use crate::models::{Message, Server, User};
+
+/// Enum to map into different models
+/// that can be saved in a snapshot
+#[derive(Serialize, Deserialize, JsonSchema, Debug)]
+#[serde(tag = "_type")]
+pub enum SnapshotContent {
+    Message(Message),
+    Server(Server),
+    User(User),
+}
+
+/// Snapshot of some content
+#[derive(Serialize, Deserialize, JsonSchema, Debug)]
+pub struct Snapshot {
+    /// Unique Id
+    #[serde(rename = "_id")]
+    pub id: String,
+    /// Report parent Id
+    pub report_id: String,
+    /// Snapshot of content
+    pub content: SnapshotContent,
+}