ClipboardJS is now deprecated

When working with the <clipboard-button> component that uses ClipboardJS under the hood, the copy function has stopped working. Looking into it further, the library we use uses document.execCommand('copy'), which is now deprecated.

• https://github.com/zenorocha/clipboard.js/blob/master/src/common/command.js

• https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand

There’s a fix that doesn’t require a library using the Clipboard API. There are certain features that it doesn’t support but it seems to work for most of our purposes

• https://developer.mozilla.org/en-US/docs/Web/API/Clipboard_API

Unfortunately, this won't work in the GDK when configured to run in the gdk.test domain, as it wouldn't be considered a Secure Context.

Locally-delivered resources such as those with http://127.0.0.1 URLs, http://localhost and http://*.localhost URLs (e.g. http://dev.whatever.localhost/), and file:// URLs are also considered to have been delivered securely.

A workaround would be to configure https locally