feat: Discussion Responses Order to Show Latest First & Fix Sorting and Filtering

[HamzaIsrar12]

Description

LEARNER-10450

Reverse Order of Responses in API:

• Responses on the post responses and comments screen should be displayed in reverse chronological order (latest first).
• Update the API request to include reverse_order=true when fetching responses.
• The order should match the web application’s behaviour.

Update "Add a Response" and "Add a Comment" Behavior:

• Newly added responses and comments should appear at the top of the list instead of the bottom.
• UI updates instantly to reflect the correct order after adding a response or comment.

Sorting & Filtering:

• Clear the list and load the first page when sorting or filtering.
• On refresh, retain the applied filter and sort order.