Make the output more usable

Currently the output is just a list like this:
```
PASS test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-ary-rest-iter.js strict mode (success) - 332/622
PASS test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-ary-rest-init.js default (success) - 333/622
PASS test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-ary-rest-iter.js default (success) - 334/622
PASS test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-exhausted.js default (success) - 335/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-cover.js strict mode (expected success, got runtime error) - 336/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-cover.js default (expected success, got runtime error) - 337/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-class.js default (expected success, got runtime error) - 338/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-class.js strict mode (expected success, got runtime error) - 339/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-arrow.js default (expected success, got runtime error) - 340/646
PASS test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-exhausted.js strict mode (success) - 341/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-arrow.js strict mode (expected success, got runtime error) - 342/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-gen.js strict mode (expected success, got runtime error) - 343/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-fn.js default (expected success, got runtime error) - 344/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-fn.js strict mode (expected success, got runtime error) - 345/646
FAIL test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-fn-name-gen.js default (expected success, got runtime error) - 346/646
PASS test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-hole.js default (success) - 347/646
PASS test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-unresolvable.js default (success) - 348/646
PASS test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-init-throws.js strict mode (success) - 349/646
```

While it's ok if it needs to be read by machines, this Test262 runner is primarly meant for people who whant to check if Babel is compliant in some features or are looking for possible PRs.

Ideally it should generate an HTML file where users can expand different sections and it shows percentages for each section.

Start by locating where the Test262 runner produces the current plain-text result list. Review the example output and determine how test results can be grouped into expandable sections with percentages. Done means the runner generates an HTML report that makes Babel compliance and potential failures easier to inspect.

Written by the indexing model from the issue text.