url: parsing should not serialize windows drive letter twice

es-modules do not currently work on Windows (we missed this when landing them initially because we'd missed adding a variable to vcbuild.bat/Makefile).

The underlying issue was that node::url::URL.path() was serializing windows style paths incorrectly if there was a drive letter in both the path and the base:

resolve("/D:/a/b/c.mjs", "file:///C:/a/b/c")

would result in an incorrect parse of /C:/D:/a/b/c.mjs.

the same parse in Chrome resolves to:

/D:/a/b/c.mjs.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

Affected core subsystem(s)

url,es-module

reviewer: @bmeck, @jasnell