feat: display which path failed to decode

[Jeff-Tian]

Why

Hello, when I started a koa server and sent a template HTML to the client, the server showed an error "failed to decode BadRequestError: failed to decode" which is not clear enough to let me spot the issue instantly.

After more investigation, I found it's caused by the URL specified in the HTML template being malformed to the koa server.

So I think it might help to let the developer know the root cause immediately by enhancing the error message to display the path that failed to decode.

Screenshots

Thanks for your time to review!

Checklist

• I have ensured my pull request is not behind the main or master branch of the original repository.
• I have rebased all commits where necessary so that reviewing this pull request can be done without having to merge it first.
• I have written a commit message that passes commitlint linting.
• I have ensured that my code changes pass linting tests.
• I have ensured that my code changes pass unit tests.
• I have described my pull request and the reasons for code changes along with context if necessary.

[Jeff-Tian]

ping