[Outreachy Task Submission] - Absence of Confirmation message on adding a post to a collection

[felabel]

When a post is added or removed from a collection, there is no confirmation message for this processes. Also after selecting a collection, there is no done or finish button for better user interactivity.

Steps to reproduce;

1. On the dashboard select your survey to view the posts in them
2. Click on the 3 dots on a post and select add to collection

Actual Behaviour
A collection modal pops up, select your collection and no confirmation message or a done button

Expected Behaviour;
There should be a snackbar notification showing the success of adding or removing a post from a collection.