[Keyboard Manager] Cleanup header file references to improve incremental build time (#4880)

* Remove WinUI include in KeyboardManagerState.h

* Changed include steps

* Clean up headers in KeyboardManagerUI except XamlBridge.h

* Cleaned up headers in KeyboardManager common and test

* Cleaned up headers in KeyboardManager project

* Removed headers from XamlBridge

* Removed some headers from kbm common pch

* Added MP flag to reduce build time

* Added missing include

src/modules/keyboardmanager/ui/Styles.h

@@ -1,6 +1,7 @@
 #pragma once
-#include <winrt/Windows.UI.Xaml.h>
+namespace winrt::Windows::UI::Xaml
+{
+    struct Style;
+}
 
-using namespace winrt::Windows::UI::Xaml;
-
-Style AccentButtonStyle();
+winrt::Windows::UI::Xaml::Style AccentButtonStyle();