[BROWSEUI][PSDK] Stubplement UserAssist

Initial implementation of `CUserAssist` class, which contains `IUserAssist` interface.
See https://www.geoffchappell.com/studies/windows/ie/browseui/classes/userassist.htm.
Required by MS shell32.dll.

CORE-17345 CORE-17393

sdk/include/psdk/shlguid.h

@@ -104,6 +104,8 @@ DEFINE_GUID(CLSID_ACListISF,      0x03c036f1, 0xa186, 0x11d0, 0x82, 0x4a, 0x00,
 DEFINE_GUID(CLSID_ACLMRU,         0x6756a641, 0xde71, 0x11d0, 0x83, 0x1b, 0x00, 0xaa, 0x00, 0x5b, 0x43, 0x83);
 DEFINE_GUID(CLSID_ACLCustomMRU,   0x6935db93, 0x21e8, 0x4ccc, 0xbe, 0xb9, 0x9f, 0xe3, 0xc7, 0x7a, 0x29, 0x7a);
 
+DEFINE_GUID(CLSID_UserAssist,     0xdd313e04, 0xfeff, 0x11d1, 0x8e, 0xcd, 0x00, 0x00, 0xf8, 0x7a, 0x47, 0x0c);
+
 #define SID_SInternetExplorer IID_IWebBrowserApp
 #define SID_SWebBrowserApp    IID_IWebBrowserApp
 #define SID_SWebBrowserEventsService IID_IWebBrowserEventsService

sdk/include/psdk/shobjidl.idl

@@ -4768,4 +4768,40 @@ interface IItemNameLimits : IUnknown
         [out] int *piMaxNameLen);
 };
 
+/*****************************************************************************
+ * IUserAssist interface
+ */
+[
+    uuid(dd313e05-feff-11d1-8ecd-0000f87a470c),
+    object,
+    local,
+    pointer_default(unique)
+]
+interface IUserAssist : IUnknown
+{
+    HRESULT FireEvent(
+        GUID const *guid,
+        INT param1,
+        ULONG param2,
+        WPARAM wparam,
+        LPARAM lparam);
+
+    HRESULT QueryEvent(
+        GUID const *guid,
+        INT param,
+        WPARAM wparam,
+        LPARAM lparam,
+        PVOID ptr);
+
+    HRESULT SetEvent(
+        GUID const *guid,
+        INT param,
+        WPARAM wparam,
+        LPARAM lparam,
+        PVOID ptr);
+
+    HRESULT Enable(
+        BOOL bEnable);
+};
+
 #endif // __REACTOS__