This commit rewrites test runner to send structured error data from JavaScript
to Rust instead of passing strings. This will allow to customize display of errors
in test report (which will be addressed in follow up commits).
Following changes were done in this commit:
- remove "test" prefix before each test
- use gray color for "running N tests from ..." prompt
- use relative path or remote URL instead of full URL in "running N tests from ..." prompt
- in "failures" section, add file path/remote URL before the test name
Co-authored-by: Yoshiya Hinosawa <stibium121@gmail.com>
