feat(donate):add donation modal and certification message

[ahmaxed]

• I have read freeCodeCamp's contribution guidelines.
• My pull request has a descriptive title (not a vague title like Update index.md)
• My pull request targets the master branch of freeCodeCamp.
• None of my changes are plagiarized from another source without proper attribution.
• All the files I changed are in the same world language (for example: only English changes, or only Chinese changes, etc.)
• My changes do not use shortened URLs or affiliate links.

Closes #XXXXX

[gitpod-io]

[ahmaxed]

This pr will display a donation message on a certificate if the username of the certificate matches the username of the signed in user.

The message will disappear for the session if user clicks on the message link and get redirected to donate page.

Additionally a modal will be displayed after the last challenge of a block has been submitted.

if either of the donation requests has been shown during a session, the other one will not be shown.

Please let me know if the logic is in place so I could proceed with tests.

[ahmaxed]

@ojeytonwilliams, could you take a quick look?

[raisedadead]

Please provide detailed context about when this modal is to be shown for QA in the OP.

[ahmaxed]

@raisedadead, the modal will be shown after the last challenge on a block has been completed.
it will check if the user has donated, if any other form of donation has been requested (certificate message) in that session.

an easy way to test it would be the data viz certificates. the donation should pop up after the last challenge has been completed.

[ojeytonwilliams]

The UX is great, but I'm not sure if it's always behaving exactly as it's supposed to and there's potentially an issue for slow connections:

[ahmaxed]

@ojeytonwilliams could you take another look?

[ojeytonwilliams]

I noticed I'd named an action badly, so I added some suggestions to fix that. I didn't change donationRequested to preventDonationRequests, because I was worried I'd miss one. I can add that as a separate commit.

As far as functionality goes, everything looks good. The following is just nitpicking about names:

[ojeytonwilliams]

Eslint's complaining about the constructor: