Build out "resource preview" for practice/exercise resources

[marcellamaki]

Overview

As we move towards an MVP of the lesson management side panel, we want to be sure that coaches can preview resources within the new workflow, without navigating away from the page and losing context.

Prerequisites

• Run Kolibri locally or kolibri-demo to get familiar with the current (0.17) lesson preview UX/UI, and then walk through the develop lesson workflow at using the /lessonstemp path.

Updated accordion styles

For 0.18, it looks like the accordion question preview is slightly updated. We should address this within this issue in a common place, as it will be used across lessons (for exercises) and quizzes, as we iterate on 0.17 work.

Tasks

• Update the KCards in the exercise selection in lessons so that they navigate to the preview
• Update the styles of the accordion - beginning with ensuring the colors, borders, padding/spacing, etc is updated. (This is detail-oriented work and will require close inspection of the Figma)

Acceptance Criteria

• User can successfully preview any exercise materials that use the content renderer - including those with and without corresponding images/content that is referenced by the question
• User can add the resource to the lesson
• proper mobile responsiveness and a11y (including the accordion navigation)

Out of scope

• Implementing this preview for non-practice resources