fix(challenges): converts delete html tests to regex

[joshalling]

Description

This code converts the tests of the Delete HTML Elements challenge to use regex instead of jQuery. This prevents some weird behavior as shown below. This change also makes it possible to add a solution to be tested with the test suite so I included that as well.

The following code currently passes, but it will not pass with this change:

Hello World</h1>

<h2>

<p>

My actual changes start on line 568 and go through 587.

Pre-Submission Checklist

• [x] Your pull request targets the dev branch.
• [x] Branch starts with either fix/, feature/, or translate/ (e.g. fix/challenge-tests)
• [x] All new and existing tests pass the command npm test.
• [x] Use npm run commit to generate a conventional commit message. Learn more here: https://conventionalcommits.org/#why-use-conventional-commits
• [x] The changes were done locally on your machine and NOT GitHub web interface. If they were done on the web interface you have ensured that you are creating conventional commit messages.

Checklist:

• [x] Tested changes locally.
• [x] Addressed currently open issue (replace XXXXX with an issue no in next line)

Closes #251

[scissorsneedfoodtoo]

Sorry for the delay in reviewing this. Everything LGTM!