New Feature: Add server-side channel unreads.

src/routes/sync/get_unreads.rs

@@ -0,0 +1,10 @@
+use crate::database::*;
+use crate::util::result::Result;
+
+use rocket_contrib::json::JsonValue;
+use mongodb::bson::doc;
+
+#[get("/unreads")]
+pub async fn req(user: User) -> Result<JsonValue> {
+    Ok(json!(user.fetch_unreads().await?))
+}