Deleting discussion-reply feature provided.

**Now replies of *Discussion* can be deleted:**
- As any of the discussion reply gets deleted:
  - An confirm-box will appear seeking final permission for the deletion.
  - Updating the text of replies-count in the discussion-tab.
  - Depending on the replies the text on button also gets modified.
    - If all the replies are deleted: ```Initiate discussion on <node name>```
- Replies deletion flow:
  - If any of the reply doesn't have any child-reply then with confirmation that reply will gets deleted.
  - If any of the reply has multiple/nested child-replies then confirm-box appear showing total no of child replies and asking for permission to delete that reply and it's child-replies.
- If unauthorized user is trying to delete the reply, alert will appear and reply will not get deleted.