feat(core): implement message model

closes #273

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

@@ -6,6 +6,7 @@ mod channel_webhooks;
 mod channels;
 mod emojis;
 mod files;
+mod messages;
 mod ratelimit_events;
 mod server_bans;
 mod server_members;
@@ -21,6 +22,7 @@ pub use channel_webhooks::*;
 pub use channels::*;
 pub use emojis::*;
 pub use files::*;
+pub use messages::*;
 pub use ratelimit_events::*;
 pub use server_bans::*;
 pub use server_members::*;