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/test/KeyboardManagerTest.vcxproj

@@ -107,6 +107,8 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="AppSpecificShortcutRemappingTests.cpp" />
+    <ClCompile Include="BufferValidationTests.cpp" />
+    <ClCompile Include="LoadingAndSavingRemappingTests.cpp" />
     <ClCompile Include="MockedInputSanityTests.cpp" />
     <ClCompile Include="SetKeyEventTests.cpp" />
     <ClCompile Include="OSLevelShortcutRemappingTests.cpp" />
@@ -114,7 +116,9 @@
     <ClCompile Include="pch.cpp">
       <PrecompiledHeader Condition="'$(CIBuild)'!='true'">Create</PrecompiledHeader>
     </ClCompile>
+    <ClCompile Include="ShortcutTests.cpp" />
     <ClCompile Include="SingleKeyRemappingTests.cpp" />
+    <ClCompile Include="KeyboardManagerHelperTests.cpp" />
     <ClCompile Include="TestHelpers.cpp" />
   </ItemGroup>
   <ItemGroup>