refactor(Core/AI): Some more refactoring prep for Comat Threat system… (#15026)

Co-authored-by: Treeston <14020072+Treeston@users.noreply.github.com>

src/server/game/AI/SmartScripts/SmartAI.h

@@ -80,7 +80,7 @@ public:
     void JustReachedHome() override;
 
     // Called for reaction at enter to combat if not in combat yet (enemy can be nullptr)
-    void EnterCombat(Unit* enemy) override;
+    void JustEngagedWith(Unit* enemy) override;
 
     // Called for reaction at stopping attack at no attackers or targets
     void EnterEvadeMode(EvadeReason why = EVADE_REASON_OTHER) override;