feat: add siegetank unit set and implement messaging system

- Created a new unit set for "siegetank" with various crew types and their attributes.
- Implemented a messaging system with types, payloads, and storage functionality.
- Added tests for the messaging system to ensure correct behavior for different message types (private, national, public, diplomacy).

packages/logic/src/index.ts

@@ -3,6 +3,7 @@ export type { RandomGenerator } from '@sammo-ts/common';
 export * from './actions/index.js';
 export * from './constraints/index.js';
 export * from './logging/index.js';
+export * from './messages/index.js';
 export * from './ports/world.js';
 export * from './ports/worldSnapshot.js';
 export * from './scenario/index.js';