Add support for embedding the scribehow links

[yash-learner]

Closes #1381

Proposed Changes

• Add scribehow_fallback_provider
• Update the oembed.rb and the resolver.rb
• Update the frontend
• Update CSP
• Check for spec updates
• Update the documentation

add_support_for_scribehow_links_embedding.mp4

@pupilfirst/developers

Merge Checklist

• Add specs that demonstrate bug / test a new feature.
• Check if route, query, or mutation authorization looks correct.
  • Add tests for authorization, if required.
• Ensure that UI text is kept in I18n files.
• Update developer and product docs, where applicable.
• Prep screenshot or demo video for changelog entry, and attach it to issue.
• Check if new tables or columns that have been added need to be handled in the following services:
  • Users::DeleteAccountService
  • Courses::CloneService
  • Courses::DeleteService
  • Courses::DemoContentService
  • Levels::CloneService
  • Schools::DeleteService
• Check if changes in packaged components have been published to npm.
• Add development seeds for new tables.
• If the updates involve Graph mutations ensure that the files are migrated to the new approach without a mutator.

[harigopal]

Everything works well!

The base branch was changed.