SOL-4828 - "Split container types between being mutable and immutable"

- Removes VUTF8String and replaces its usage with VArray's of Char8's.
- Reworks VUniqueString to derive from VArray
- Re-enables majority of string related verse-tests for VM

Minor:
- Updated some ToStringImpl for VFalse and VFunction

#okforversepublic
#rb saam.barati, Tim.Smith
#rb tim.smith

[CL 32803034 by jared cotton in ue5-main branch]

Engine/Source/Programs/UnrealBuildTool/System/VerseVMBytecodeGenerator.cs

@@ -924,8 +924,8 @@ namespace UnrealBuildTool
 			Inst("NewClass")
 				.Arg("Dest", Role.UnifyDef)
 				.Arg("Package", Role.Immediate, Arity.Fixed, "VPackage")
-				.Arg("Name", Role.Immediate, Arity.Fixed, "VUTF8String")
-				.Arg("UEMangledName", Role.Immediate, Arity.Fixed, "VUTF8String")
+				.Arg("Name", Role.Immediate, Arity.Fixed, "VArray")
+				.Arg("UEMangledName", Role.Immediate, Arity.Fixed, "VArray")
 				.Const("ClassKind", CppType.ClassKind)
 				.Const("bNative", CppType.Bool)
 				.Arg("Inherited", Role.Use, Arity.Variadic)