Improve error handling by displaying an error message (#1075)

* wire up error messages

* more errors

* fix crash on render error

* Always show copy and cut

* PR comments

* Fix spelling

src/GraphingInterfaces/IGraph.h

@@ -18,6 +18,8 @@ namespace Graphing
 
         virtual std::optional<std::vector<std::shared_ptr<IEquation>>> TryInitialize(const IExpression* graphingExp = nullptr) = 0;
 
+        virtual HRESULT GetInitializationError() = 0;
+
         virtual IGraphingOptions& GetOptions() = 0;
 
         virtual std::vector<std::shared_ptr<Graphing::IVariable>> GetVariables() = 0;