test_runner: exclude mocked CJS modules from coverage

[ThanhNguyxn]

Summary

• Fix coverage report incorrectly including mocked CJS modules when imported into ESM
• Add regression test for CJS module mocking scenario

Description

When a CommonJS module is mocked and imported into an ESM module, the coverage report incorrectly includes the mocked module. This happens because V8 coverage reports use the original file URL without the mock search parameter (?node-test-mock=X) that the ESM loader adds.

Root Cause

PR #59348 fixed issue #59112 by checking if a coverage URL contains the kMockSearchParam query parameter to exclude mocked modules. However, this only works for ESM-to-ESM mocking because:

1. The ESM loader's resolve hook adds the mock search param to the URL
2. V8 coverage reports the URL with the search param for ESM modules
3. But for CJS modules, V8 coverage reports the original file URL without the search param

Solution

In shouldSkipFileCoverage(), after checking the URL search params, also check if the base URL (without query params) is registered in the mocks registry with active: true.

Reproduction (from #61709)

// dependency.cjs
module.exports = { sum: (a, b) => a + b };

// subject.mjs  
import { sum } from './dependency.cjs';
export const theModuleSum = (a, b) => sum(a, b);

// test.mjs
import { mock } from 'node:test';
mock.module('./dependency.cjs', { namedExports: { sum: () => 42 } });
const { theModuleSum } = await import('./subject.mjs');
// dependency.cjs incorrectly appears in coverage report

Fixes: #61709

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner