url: build warning fixes

Checklist

• make -j8 test (UNIX [macOS]; Linux i386 & amd64) and vcbuild test nosign (.\vcbuild.bat nosign then .\vcbuild.bat test nosign nobuild as Administrator on Windows) PASS OK
• commit message follows commit guidelines

Additional item

• I hereby certify the statements in Developer's Certificate of Origin 1.1

Affected core subsystem(s)

url

Description of change

• mark ignored return value in node::url::Parse(...) (originally in #9757)
• use URL_FAILED instead of FAILED macro to resolve macro redefinition warning on Windows