test, url: check the origin of the blob URLs

[watilde]

In the getter of the origin in URL, the URL that has blob protocol will be parsed in a function called "originFor". Add test cases to the url-tests-additional fixture to test that.

This test increases the coverage of internal/url.js:

• https://coverage.nodejs.org/coverage-3429991d8b43474c/root/internal/url.js.html

The following lines will be covered:

• node/lib/internal/url.js

  Lines 1064 to 1073 in a196895

  	case 'blob:':
  	if (url[context].path && url[context].path.length > 0) {
  	try {
  	return (new URL(url[context].path[0])).origin;
  	} catch (err) {
  	// fall through... do nothing
  	}
  	}
  	origin = new OpaqueOrigin();
  	break;

Checklist

• make -j4 test passes
• tests are included
• commit message follows commit guidelines

Affected core subsystem(s)

test, url