Merge Staging

[brueningf]

This pull request includes changes to the EnrollButton and HorizontalCourseCard components to improve their functionality and appearance. The most important changes include adding a string truncation function, modifying the EnrollButton to support a compact mode, and updating the layout and styling of the HorizontalCourseCard.

Changes to EnrollButton:

• Added a truncateString function to limit the length of strings and appended ellipses if necessary. (frontend/src/app/courses/[slug]/EnrollButton.tsxL11-R16)
• Modified the EnrollButton component to accept a compact prop, which adjusts the text size and truncates the assignment title if needed. (frontend/src/app/courses/[slug]/EnrollButton.tsxL130-R142)

Changes to HorizontalCourseCard:

• Simplified the layout by removing unnecessary width and height constraints from the article and figure elements.
• Adjusted the description container to have a maximum height and added a new container for the certificate link.
• Updated the EnrollButton within the course card to use the new compact mode.
• Added a margin-top to the progress bar container for better spacing.