fix: include the correct SCSS file for lti_block

[kdmccormick]

Testing

I confirmed this fix using Tutor and an export of the course from the original (private) bug report. Here's how I tested.

Setup:

• Running instance of Studio & LMS
• Course exists with "lti" added as an Advanced Module Type (in Advanced Settings) and a unit containing an "LTI" component (not an "LTI Consumer" component -- that is a newer implementation of the block, which didn't suffer from this bug).
• LTI component should be pre-configured with an external resource.
• Logged-in user can edit course

Bug reproduction (master)

• Go to unit in Studio
• Hit "Edit" on LTI component
• Editor should show error message containing Error: Sass not found: /edx/app/edxapp/edx-platform/xmodule/assets/LTIBlockEditor.scss
• Hit "View Live"
• LTI contents should be squished into a very small frame in LMS -- about 300x400, by my guess.
• Open network log, hard-refresh, and confirm that LTIBlockDisplay.css is NOT loaded.

Bug fix confirmation (this branch):

• Go to unit in Studio
• Hit "Edit" on LTI component
• Confirm that editor displays and works.
• Hit "View Live"
• LTI contents should display in LMS in a frame of appropriate size.
• Open network log, hard-refresh, and confirm that LTIBlockDisplay.css IS loaded.

Description

lti_block has Sass for its display, but not for its editor.

During the add_sass_to_fragment refactoring, I mixed this up: I added a non-existent scss file to the studio_view but didn't add the actual scss file to the student_view.

Course authors using the (deprecated) lti_block saw:

We're having trouble rendering your component
Students will not be able to access this component. Re-edit your component to fix the error.

Error: Sass not found: /edx/app/edxapp/edx-platform/xmodule/assets/LTIBlockEditor.scss

as a result of this bug.

Original PR: #32592

Private-ref: https://2u-internal.atlassian.net/browse/TNL-11029

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX staging environment in preparation for a release to production.

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX production environment.