refactor: combine models and db crate together

crates/core/database/src/models/mod.rs

@@ -0,0 +1,22 @@
+mod admin_migrations;
+mod bots;
+
+pub use admin_migrations::*;
+pub use bots::*;
+
+use crate::{Database, MongoDb, ReferenceDb};
+
+pub trait AbstractDatabase: Sync + Send + admin_migrations::AbstractMigrations {}
+impl AbstractDatabase for ReferenceDb {}
+impl AbstractDatabase for MongoDb {}
+
+impl std::ops::Deref for Database {
+    type Target = dyn AbstractDatabase;
+
+    fn deref(&self) -> &Self::Target {
+        match &self {
+            Database::Reference(dummy) => dummy,
+            Database::MongoDb(mongo) => mongo,
+        }
+    }
+}