Factorize input hooks into reusable monitor classes

Those monitors will need some context so this will be useful
in the nearby future.

src/duckstation-qt/duckstation-qt.vcxproj

@@ -66,6 +66,7 @@
     <ClCompile Include="displaysettingswidget.cpp" />
     <ClCompile Include="hotkeysettingswidget.cpp" />
     <ClCompile Include="inputbindingdialog.cpp" />
+    <ClCompile Include="inputbindingmonitor.cpp" />
     <ClCompile Include="inputbindingwidgets.cpp" />
     <ClCompile Include="qtdisplaywidget.cpp" />
     <ClCompile Include="gamelistsettingswidget.cpp" />
@@ -105,6 +106,7 @@
     <QtMoc Include="gamelistmodel.h" />
     <QtMoc Include="gamelistsearchdirectoriesmodel.h" />
     <QtMoc Include="autoupdaterdialog.h" />
+    <ClInclude Include="inputbindingmonitor.h" />
     <ClInclude Include="resource.h" />
     <ClInclude Include="settingwidgetbinder.h" />
     <QtMoc Include="consolesettingswidget.h" />