Add a URL type that attempts a fetch to check the link

[andymeneely]

Whenever we ask curators to specify a link, let's

• Check that it fits a valid URL, probably using the JS URL class
• Check if that link actually goes somewhere.

Now, we need to make sure we're not facilitating CSRF though.

[brianravi]

Validation is now in place for URL js type format on my branch.

I am presently looking at ways to check if the URL is a valid page, as CORS may prevent a domain from accurately reporting a requested page's existence.

I would not want to prevent a user from saving a URL in the event that the remote server 'says' it doesnt exist or is blocked.

[andymeneely]

Yeah based on our discussion let's remove the link checking thing

[brianravi]

understood, as mentioned on today's call, URL type validation is now in place in the wizard branch