feat(Discussion): Summarize student responses in grading tool

[hirokiterashima]

Notes

Please style and change the system prompt as you see fit

Changes

For units with AI enabled (see "Test Prep" below), in the CM for any Discussion item:

• Show "Generate Student Summary" button if there is at least one post for the period selected (includes when "All Periods" is selected)
  • Clicking on the button generates summary and displays it.
    • Show spinner while waiting
    • Shows summary in the same language as the prompt
    • Show (# responses) after summary
  • Summary is saved in localStorage. Coming back to the component should re-display the summary
  • Clicking on the button again generates new summary and overwrites the existing one.
• Show "No student responses" if there is no post for the period selected

Test Prep

Add top-level json field in the unit to enable this feature:

{
...
"ai": { "enabled": true }
...
}

Test

• Changes work as described above
• Units that don't have AI enabled do not show the Discussion summarizer

[breity]

Looks good. Time of summary generated isn't showing up. As discussed, @hirokiterashima will fix in feature branch.