Add click-to-copy feature

[DimK19]

Made a very small addition using the Clipboard API. I ran npm test locally, apparently the two failing tests are unrelated to it. Hope it works properly!

[KrisXV]

Hey! Sorry for the delay; could you provide a screenshot of how this looks?

[DimK19]

Hello! Here's how it looks currently (my mouse pointer is not showing on the screenshot, but is on the main result sentence and changes to "hand-pointer")

Since opening the request, I've thought of making a tooltip pop up after clicking, as a confirmation, but it is not ready yet. Also, I noticed the failing tests have been fixed in subsequent pr's, so if you could tell me how to fix them I'll do it here too. Thanks.

[DimK19]

I had trouble syncing my fork with the latest build, so I just hard reset and made a new commit. Now it is passing all the tests locally.

The pop-up tooltip disappears after 2 seconds.

[DimK19]

@KrisXV Hello, I am re-opening this because the feature would be quite useful. It is still requested by this issue: #348, under "Approved Features". Details with screenshots in the messages above.
Please let me know if any changes must be made. Thanks.

[AustinXII]

@DimK19 sorry for the late replies, I will look at this today and get back to you. It looks pretty good at a click glance though!

[monsanto]

Seems like useful functionality, hopefully Austin will review it but if it doesn't happen I will.

[AustinXII]

Thanks!