This commit adds "Deno.core.setFormatExceptionCallback" which
can be used to provide custom formatting for errors. It is useful
in cases when user throws something that is non-Error (eg.
a string, plain object, etc).
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>
