Warn quoted component name

[leana8959]

• Patches conform to the coding conventions.
• Any changes that could be relevant to users have been recorded in the changelog.
  • Is the change significant? If so, remember to add significance: significant in the changelog file.
• The documentation has been updated, if necessary.
• Manual QA notes have been included.
• Tests have been added. (Ask for help if you don’t know how to write them! Ask for an exemption if tests are too complex for too little coverage!)

[ffaf1]

Thanks!

[jappeace]

The warning here will tell users to stop doing this in their own development environment (effectively deprecating it).

I suggest we make cabal check error on quoted components so that we at least aren't allowed to upload new packages with quotes to hackage.