Give users a hint if you redirect on an unfound package #2181
Description
Go to https://pub.dartlang.org/packages/not_a_package
Redirect to https://pub.dartlang.org/packages?q=not_a_package
No hint that I was redirected – maybe redirect to
https://pub.dartlang.org/packages?q=not_a_package&prompt=bad_package_name or similar and show a message that the package in question doesn't exist
...I don't like unexpected redirect behavior :-)