fix: allow set cookies with localhost

Adding more tests to cover the breaking use cases noted in #246.

e.g.;.
* `new CookieJar().setCookieSync("settingThisShouldPass=true; Domain=localhost; Path=/;", "http://localhost")`

Also modifies the assertion for a test introduced in #221 that may be incorrect.

lib/pubsuffix-psl.js

@@ -60,7 +60,7 @@ function getPublicSuffix(domain, options = {}) {
 
   if (!ignoreError && SPECIAL_USE_DOMAINS.includes(topLevelDomain)) {
     if (allowSpecialUseDomain) {
-      return "";
+      return topLevelDomain;
     }
     throw new Error(
       `Cookie has domain set to the public suffix "${topLevelDomain}" which is a special use domain. To allow this, configure your CookieJar with {allowSpecialUseDomain:true, rejectPublicSuffixes: false}.`