fix: fix build issue in Unvirt and LibCmo

- fix build issue in Unvirt and LibCmo
- due to we use UTF8 string. the accessible value generator in EnumsMigration need to be changed at the same time.
- remove string helper in Unvirt because we no longer need it.

Unvirt/CMakeLists.txt

@@ -5,7 +5,6 @@ target_sources(Unvirt
 PRIVATE
 	AccessibleValue.cpp
 	CmdHelper.cpp
-	StringHelper.cpp
 	StructFormatter.cpp
 	TerminalHelper.cpp
 	UnvirtContext.cpp
@@ -18,7 +17,6 @@ FILE_SET HEADERS
 FILES
 	AccessibleValue.hpp
 	CmdHelper.hpp
-	StringHelper.hpp
 	StructFormatter.hpp
 	TerminalHelper.hpp
 	UnvirtContext.hpp