Refactored Keyboard Manager UI code and added unit tests for Keyboard Manager UI (#5718)

* Added tests for loading and saving remappings in the UI

* Added tests for ApplyRemappings methods

* Moved single key remap validation logic to separate method so that it can be tested

* Added tests for single key remap validation in UI

* Refactored shortcut validation code to be testable

* Added some shortcut validation tests

* Refactored code to be cleaner

* Added tests for action key and modifier key selection and formatted file

* Added tests for selecting None

* Added tests for selecting Null

* Added tests for WinL error

* Added CtrlAltDel tests

* Added tests for MapToSameKey

* Added tests for mapping repeated shortcut

* Fixed const correctness

* Clean up type names with type alias

* Clean up ValidateAndUpdateKeyBufferElement tests and tweak ValidateShortcutBufferElement signature

* Fixed bug when None selected

* Refactored one test as per test case framework

* Cleaned up more tests

* Cleaned up buffer validation tests

* Added tests for KBM Common Helpers and Shortcut

src/modules/keyboardmanager/common/Shortcut.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "ModifierKey.h"
+#include <variant>
 class InputInterface;
 class LayoutMap;
 namespace KeyboardManagerHelper
@@ -26,6 +27,9 @@ public:
     // Constructor to initialize Shortcut from it's virtual key code string representation.
     Shortcut(const std::wstring& shortcutVK);
 
+    // Constructor to initialize shortcut from a list of keys
+    Shortcut(const std::vector<DWORD>& keys);
+
     // == operator
     inline bool operator==(const Shortcut& sc) const
     {
@@ -166,3 +170,7 @@ public:
     // Function to check if the shortcut is illegal (i.e. Win+L or Ctrl+Alt+Del)
     KeyboardManagerHelper::ErrorType IsShortcutIllegal() const;
 };
+
+using RemapBufferItem = std::vector<std::variant<DWORD, Shortcut>>;
+using RemapBufferRow = std::pair<RemapBufferItem, std::wstring>;
+using RemapBuffer = std::vector<RemapBufferRow>;