feat: Add HTML support in explanation

[abodacs]

Description

This PR adds HTML support in explanations within DnDv2

After:

Supporting information
OpenCraft internal ticket : BB-6630

Testing instructions

1. Checkout this branch in <devstack_parent>/src directory in your local setup
2. log in to Studio shell, switch to edxapp virtual env
3. Go to /edx/src/xblock-drag-and-drop-v2 and run pip install -e .
4. enable the Drag and Drop XBlock in Studio
5. Go to Studio UI and create a new unit
6. Select Problem > Advanced > Drag and Drop, to create a v2 drag and drop XBlock
7. Click Edit and change mode to Assessment
8. Scroll down to Explanation Text like Test HTML 12m<sup>2</sup>
9. Add some text in the text area
10. Click Continue twice and Save
11. Click on View Live Version
12. Ensure there is no extra line as shown above
13. Do as many attempts as required till "Show Answer" button is active
14. Click on Show Answer
15. Ensure Explanation is rendered like 'Test HTML 12m²'

Deadline

"None"

[openedx-webhooks]

Thanks for the pull request, @abodacs! Please note that it may take us up to several weeks or months to complete a review and merge your PR.

Feel free to add as much of the following information to the ticket as you can:

• supporting documentation
• Open edX discussion forum threads
• timeline information ("this must be merged by XX date", and why that is)
• partner information ("this is a course on edx.org")
• any other information that can help Product understand the context for the PR

All technical communication about the code itself will be done via the GitHub pull request interface. As a reminder, our process documentation is here.

Please let us know once your PR is ready for our review and all tests are green.

[openedx-webhooks]

Thanks for the pull request, @abodacs! Please note that it may take us up to several weeks or months to complete a review and merge your PR.

Feel free to add as much of the following information to the ticket as you can:

• supporting documentation
• Open edX discussion forum threads
• timeline information ("this must be merged by XX date", and why that is)
• partner information ("this is a course on edx.org")
• any other information that can help Product understand the context for the PR

All technical communication about the code itself will be done via the GitHub pull request interface. As a reminder, our process documentation is here.

Please let us know once your PR is ready for our review and all tests are green.

⚠️ We can't start reviewing your pull request until you've submitted a signed contributor agreement or indicated your institutional affiliation. Please see the CONTRIBUTING file for more information. If you've signed an agreement in the past, you may need to re-sign. See The New Home of the Open edX Codebase for details.

[natabene]

@abodacs Thanks for the PR, we will be waiting for the CLA check to go green first.

[tecoholic]

@abodacs Looks close to being done. Thank you for your patience. I have added a couple of suggestions. I will add my approval once those are addressed.

[tecoholic]

@abodacs 👍

• I tested this: Entered HTML in the explanation box and verified that it renders properly in the window
• I read through the code
• I checked for accessibility issues
• Includes documentation - NA

[Agrendalath]

This one looks mostly good. I left few small comments.

[Agrendalath]

@natabene, would you like to take a look at this before we merge it?

[natabene]

@Agrendalath I personally don't, but maybe @jmbowman wants.

[Agrendalath]

👍

• I tested this: checked that explanations render HTML correctly; verified Maple and Master compatibility
• I read through the code
• I checked for accessibility issues: n/a
• Includes documentation: n/a
• I made sure any change in configuration variables is reflected in the corresponding client's configuration-secure repository: n/a

[e0d]

Did this change consider implications for cross-site scripting (XSS)? If we're adding HTML support we should ensure that we're not creating an XSS issues. There are some useful docs here.

[openedx-webhooks]

@abodacs 🎉 Your pull request was merged! Please take a moment to answer a two question survey so we can improve your experience in the future.

[openedx-webhooks]

@abodacs 🎉 Your pull request was merged! Please take a moment to answer a two question survey so we can improve your experience in the future.