Use case sensitivity when checking reserved words (PHNX-1040) (#3) (#351)

Motivation
-------------
Open API generator previously wasn't case sensitive when checking for reserved words in the typescript generator. This will allow us to have the "Package" model in ProductCatalogs without needing to rename anything.

Modifications
------------------
Duplicated the C# logic for reserved words (per the @jimschubert from openapitools' suggestion)

Author: gbrown-ce

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractTypeScriptClientCodegen.java

@@ -48,7 +48,9 @@ public AbstractTypeScriptClientCodegen() {
         importMapping.clear();
 
         supportsInheritance = true;
-        setReservedWordsLowerCase(Arrays.asList(
+        
+        // NOTE: TypeScript uses camel cased reserved words, while models are title cased. We don't want lowercase comparisons.
+        reservedWords.addAll(Arrays.asList(
                 // local variable names used in API methods (endpoints)
                 "varLocalPath", "queryParameters", "headerParams", "formParams", "useFormData", "varLocalDeferred",
                 "requestOptions",
@@ -344,6 +346,12 @@ public String toDefaultValue(Schema p) {
         }
 
     }
+    
+    @Override
+    protected boolean isReservedWord(String word) {
+        // NOTE: This differs from super's implementation in that TypeScript does _not_ want case insensitive matching.
+        return reservedWords.contains(word);
+    }
 
     @Override
     public String getSchemaType(Schema p) {