More uses of AUDACITY_DLL_API...

... in many places where the function call will later need to be between
modules (or libraries, or the executable) and the annotation will be a necessity
to keep the linkage working on Windows.

That's all that this sweeping commit does.

src/toolbars/ControlToolBar.h

@@ -29,7 +29,7 @@ class AButton;
 class AudacityProject;
 
 // In the GUI, ControlToolBar appears as the "Transport Toolbar". "Control Toolbar" is historic.
-class ControlToolBar final : public ToolBar {
+class AUDACITY_DLL_API ControlToolBar final : public ToolBar {
 
  public:
 

src/toolbars/SelectionBar.h

@@ -42,7 +42,7 @@ class AudacityProject;
 class SelectionBarListener;
 class NumericTextCtrl;
 
-class SelectionBar final : public ToolBar {
+class AUDACITY_DLL_API SelectionBar final : public ToolBar {
 
  public:
    SelectionBar( AudacityProject &project );

src/toolbars/ToolBar.h

@@ -88,7 +88,7 @@ enum { ToolBarFloatMargin = 1 };
 
 class AudacityProject;
 
-class ToolBar /* not final */
+class AUDACITY_DLL_API ToolBar /* not final */
 : public wxPanelWrapper
 , protected PrefsListener
 {
@@ -254,7 +254,7 @@ public:
    friend class ToolBarResizer;
 };
 
-struct RegisteredToolbarFactory {
+struct AUDACITY_DLL_API RegisteredToolbarFactory {
    using Function = std::function< ToolBar::Holder( AudacityProject & ) >;
    using Functions = std::vector< Function >;
 

src/toolbars/ToolManager.h

@@ -47,7 +47,7 @@ class ToolFrame;
 /// class ToolManager
 ////////////////////////////////////////////////////////////
 
-class ToolManager final
+class AUDACITY_DLL_API ToolManager final
    : public wxEvtHandler
    , public wxEventFilter
    , public ClientData::Base
@@ -221,7 +221,7 @@ public:
 
 // Construct a static instance of this class to add a menu item that shows and
 // hides a toolbar
-struct AttachedToolBarMenuItem : CommandHandlerObject {
+struct AUDACITY_DLL_API AttachedToolBarMenuItem : CommandHandlerObject {
    AttachedToolBarMenuItem(
       ToolBarID id, const CommandID &name, const TranslatableString &label_in,
       const Registry::OrderingHint &hint = {},