url: reduce pathToFileURL cpp calls

[anonrig]

My local benchmarks show the following changes:

                                                                                                                 confidence improvement accuracy (*)   (**)  (***)
url/whatwg-url-to-and-from-path.js n=1000000 method='fileURLToPath' input='file:///dev/null?key=param&bool'             ***     12.59 %       ±1.21% ±1.62% ±2.12%
url/whatwg-url-to-and-from-path.js n=1000000 method='fileURLToPath' input='file:///dev/null?key=param&bool#hash'        ***      9.72 %       ±0.70% ±0.94% ±1.22%
url/whatwg-url-to-and-from-path.js n=1000000 method='fileURLToPath' input='file:///dev/null'                            ***     18.85 %       ±1.02% ±1.36% ±1.78%
url/whatwg-url-to-and-from-path.js n=1000000 method='pathToFileURL' input='file:///dev/null?key=param&bool'             ***     11.93 %       ±0.78% ±1.04% ±1.35%
url/whatwg-url-to-and-from-path.js n=1000000 method='pathToFileURL' input='file:///dev/null?key=param&bool#hash'        ***     10.31 %       ±0.67% ±0.89% ±1.16%
url/whatwg-url-to-and-from-path.js n=1000000 method='pathToFileURL' input='file:///dev/null'                            ***     18.86 %       ±1.25% ±1.67% ±2.18%

Be aware that when doing many comparisons the risk of a false-positive result increases.
In this case, there are 6 comparisons, you can thus expect the following amount of false-positive results:
  0.30 false positives, when considering a   5% risk acceptance (*, **, ***),
  0.06 false positives, when considering a   1% risk acceptance (**, ***),
  0.01 false positives, when considering a 0.1% risk acceptance (***)

[nodejs-github-bot]

Review requested:

• @nodejs/url

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/52673/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/52739/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/52756/

[anonrig]

@nodejs/url ping

[nodejs-github-bot]

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