Include the juce::WindowsHooks for keyboard access

VST3 pretends to help with the keyboard. JUCE works aroudn this
by hacking into the windows event queue. To do that you need to
set that up, and the shim did not.

Now the shim does.

src/sst/clap_juce_shim/clap_juce_shim_impl.cpp

@@ -23,6 +23,10 @@
 
 #include <memory>
 
+#if JUCE_WINDOWS
+#include <juce_gui_basics/native/juce_WindowsHooks_windows.h>
+#endif
+
 #define FLF __FILE__ << ":" << __LINE__ << " " << __func__ << " "
 
 #define DO_TRACE 0
@@ -42,6 +46,10 @@ namespace details
 {
 struct Implementor
 {
+#if JUCE_WINDOWS
+    juce::detail::WindowsHooks hooks;
+#endif
+
     struct ImplParent : juce::Component
     {
         std::string displayName;