MLS for Quick Chat (#686)

## Description:
<img width="842" alt="スクリーンショット 2025-05-09 17 51 27"
src="https://github.com/user-attachments/assets/b9a2cb5b-74d2-4c07-aed2-01d719de6eb4"
/>

MLS
## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

src/core/game/GameImpl.ts

@@ -606,6 +606,28 @@ export class GameImpl implements Game {
     });
   }
 
+  displayChat(
+    message: string,
+    category: string,
+    variables: Record<string, string> = {},
+    playerID: PlayerID | null,
+    isFrom: boolean | null = null,
+    recipient: string,
+  ): void {
+    let id = null;
+    if (playerID != null) {
+      id = this.player(playerID).smallID();
+    }
+    this.addUpdate({
+      type: GameUpdateType.DisplayChatEvent,
+      key: message,
+      category: category,
+      variables: variables,
+      playerID: id,
+      isFrom: isFrom,
+      recipient: recipient,
+    });
+  }
   addUnit(u: Unit) {
     this.unitGrid.addUnit(u);
   }