Common: Replace Result with C++23's std::expected.

Source/Core/DolphinLib.props

@@ -154,7 +154,6 @@
     <ClInclude Include="Common\Projection.h" />
     <ClInclude Include="Common\QoSSession.h" />
     <ClInclude Include="Common\Random.h" />
-    <ClInclude Include="Common\Result.h" />
     <ClInclude Include="Common\scmrev.h" />
     <ClInclude Include="Common\ScopeGuard.h" />
     <ClInclude Include="Common\SDCardUtil.h" />