Fix marketSearch parsing errors escaping the callback

[tarikermis]

Fixes #198.

A malformed percent-encoded item name makes marketSearch() throw a URIError from its HTTP response handler, so callers cannot handle the failure through their callback.

This catches listing-parser errors and passes them to the existing error-first callback. Parsing stops on the failing page without returning partial results. Valid names still decode normally, and exceptions thrown by the caller’s callback still propagate.

Verification: node test/marketSearch.malformedUri.test.js passes with mocked responses covering malformed UTF-8, invalid percent escapes, valid Unicode, pagination, and callback exceptions. The same test fails against unchanged upstream code with the malformed-URI error. node --check classes/CMarketSearchResult.js and git diff --check also pass. No live Steam requests were used.

Best Regards, Tarik