[lint] url encode lint message
This is so that things like newlines will be rendered by github
correctly. Sadly problem matchers don't work with multiline messages
(see https://github.com/actions/toolkit/issues/319), so this just uses
workflow syntax commands
(https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-a-warning-message)
directly to show annotations.
This has the extra bonus that we can make the title nicer as well.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/76351
Approved by: https://github.com/janeyx99
