Typescript nullable (#1730)

* fix name sanitation when using kebab case filenaming

* remove whitespaces

* nullable

* remove test comment

Author: smasala

modules/openapi-generator/src/main/resources/typescript-angular/modelGeneric.mustache

@@ -5,6 +5,6 @@ export interface {{classname}}{{#allParents}}{{#-first}} extends {{/-first}}{{{.
      * {{{description}}}
      */
     {{/description}}
-    {{#isReadOnly}}readonly {{/isReadOnly}}{{{name}}}{{^required}}?{{/required}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}};
+    {{#isReadOnly}}readonly {{/isReadOnly}}{{{name}}}{{^required}}?{{/required}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{#isNullable}} | null{{/isNullable}};
 {{/vars}}
 }{{>modelGenericEnums}}

modules/openapi-generator/src/main/resources/typescript-angular/modelTaggedUnion.mustache

@@ -10,7 +10,7 @@ export interface {{classname}} { {{>modelGenericAdditionalProperties}}
     * {{{description}}}
     */
     {{/description}}
-    {{name}}{{^required}}?{{/required}}: {{#discriminatorValue}}'{{discriminatorValue}}'{{/discriminatorValue}}{{^discriminatorValue}}{{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{/discriminatorValue}};
+    {{name}}{{^required}}?{{/required}}: {{#discriminatorValue}}'{{discriminatorValue}}'{{/discriminatorValue}}{{^discriminatorValue}}{{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{/discriminatorValue}}{{#isNullable}} | null{{/isNullable}};
 {{/allVars}}
 }
 {{>modelGenericEnums}}