upgrade to JUCE 5.4.3. Remove (probably) unused JUCE modules. Remove VST2 target (it's been end-of-life'd by Steinberg and by JUCE)

modules/juce_core/maths/juce_Expression.h

@@ -136,7 +136,7 @@ public:
         class Visitor
         {
         public:
-            virtual ~Visitor() {}
+            virtual ~Visitor() = default;
             virtual void visit (const Scope&) = 0;
         };
 
@@ -243,10 +243,6 @@ private:
     //==============================================================================
     class Term;
     struct Helpers;
-    friend class Term;
-    friend struct Helpers;
-    friend struct ContainerDeletePolicy<Term>;
-    friend class ReferenceCountedObjectPtr<Term>;
     ReferenceCountedObjectPtr<Term> term;
 
     explicit Expression (Term*);