Split off Case Insensitive const string.

tests/ConstStringTests.cpp

@@ -2,6 +2,7 @@
 #include <cstring>
 #include <unordered_map>
 #include "../extern/catch.hpp"
+#include "../src/CaseInsensitiveConstString.hpp"
 #include "../src/ConstString.hpp"
 
 TEST_CASE("Use const string in unordered_map", "[Utilities]") {
@@ -24,7 +25,7 @@ TEST_CASE("Use const string in switch case", "[Utilities]") {
 }
 
 TEST_CASE("Use insensitive const string in unordered_map", "[Utilities]") {
-    std::unordered_map<Arbutils::ConstString, int32_t> map;
+    std::unordered_map<Arbutils::CaseInsensitiveConstString, int32_t> map;
     map.insert({"foO"_cnc, 1});
     map.insert({"bAR"_cnc, 5});
 
@@ -33,7 +34,7 @@ TEST_CASE("Use insensitive const string in unordered_map", "[Utilities]") {
 }
 
 TEST_CASE("Use case insensitive const string in switch case", "[Utilities]") {
-    auto val = Arbutils::ConstString::CaseInsensitive("foobar");
+    auto val = Arbutils::CaseInsensitiveConstString("foobar");
     switch (val){
         case "foo"_cnc: FAIL(); break;
         case "bar"_cnc: FAIL(); break;