CStringExtras: Prevent potential out of bounds reads with CompareCaseInsensitive

The strcasecmp and _stricmp functions expect the passed in strings to
be null-terminated, however we we're also exposing a std::string_view
overload for that function. std::string_view instances aren't required
to be null-terminated, so this makes the interface a little unsafe.

We can use std::lexicographical_compare() to provide the same behavior
and also properly handle the case of non-null-terminated strings.

Runtime/World/CScriptStreamedMusic.cpp

@@ -10,8 +10,9 @@
 namespace urde {
 
 bool CScriptStreamedMusic::IsDSPFile(std::string_view fileName) {
-  if (!CStringExtras::CompareCaseInsensitive(fileName, "sw"))
+  if (CStringExtras::CompareCaseInsensitive(fileName, "sw")) {
     return true;
+  }
   return CStringExtras::IndexOfSubstring(fileName, ".dsp") != -1;
 }