[Refactor]Port C++/CX to C++/WinRT (#34198)

## Summary of the Pull Request
Removes all C++/CX code, replacing it with C++/WinRT.

## Detailed Description of the Pull Request / Additional comments
Removes all C++/CX code.
Renames interop namespaces to be better consumed by CsWinRT.
Standardizes all projects on net8.0-windows10.0.20348.0, which is a
requirement for C++/WinRT usage.
FileLocksmithLibInterop brought to stdcpplatest and static analysis
errors were corrected.
Removed now unneeded string conversion code from
FileLocksmithLibInterop.
Changed interop KeyboardHook to use a single hook across all instances.
Required because on C++/WinRT we don't have the .NET runtime to bind a
object instance to a delegate and be able to pass it to a C function
pointer argument (still no idea why this worked correctly on C++/CX to
be honest). This change actually makes us create less low level keyboard
hooks.
Changed some code that depended on arrays since WinRT/C++ returns null
instead of an empty array through the interface.

## Validation Steps Performed
Built and tested runtime.

src/common/interop/HotkeyManager.idl

@@ -0,0 +1,23 @@
+namespace PowerToys
+{
+    namespace Interop
+    {
+        struct Hotkey
+        {
+            Boolean Win;
+            Boolean Ctrl;
+            Boolean Shift;
+            Boolean Alt;
+            UInt8 Key;
+        };
+        delegate void HotkeyCallback();
+
+        [default_interface] runtimeclass HotkeyManager : Windows.Foundation.IClosable
+        {
+            HotkeyManager();
+            UInt16 RegisterHotkey(Hotkey _hotkey, HotkeyCallback _callback);
+            void UnregisterHotkey(UInt16 _handle);
+        }
+
+    }
+}