feat(core): add raw db statisics endpoint for admin panel

crates/quark/src/traits/admin/stats.rs

@@ -0,0 +1,6 @@
+use crate::{models::stats::Stats, Result};
+
+#[async_trait]
+pub trait AbstractStats: Sync + Send {
+    async fn generate_stats(&self) -> Result<Stats>;
+}