refactor: Rewrite BehaviorMessage classes to use member initialization, preferred member naming conventions, and const-ref getters (#1456)

* Split out BehaviorMessage class changes from PR #1452

* remove <string_view> inclusion in ActionContext.h

* add the arguments nullptr check back in

* remove redundant std::string constructor calls

* Update AddStripMessage.cpp - change push_back to emplace_back

dGame/dPropertyBehaviors/State.h

@@ -7,11 +7,12 @@ class AMFArrayValue;
 
 class State {
 public:
-	template<typename Msg>
+	template <typename Msg>
 	void HandleMsg(Msg& msg);
 
 	void SendBehaviorBlocksToClient(AMFArrayValue& args) const;
 	bool IsEmpty() const;
+
 private:
 	std::vector<Strip> m_Strips;
 };