Implement likes functionality

[shreyasgoyal213]

Implement the frontend for the likes functionality.

Overview

• If a user clicks the 'like' button on a post, call the endpoint that adds the user to the likes of the post. Also, add an indication that the post has been liked, such as fill the heart with pink.
• Should show a post as 'liked' if the user has previously liked the post.
• A user should be able to remove their like from a post by clicking the like button again. Call the endpoint that removes the user from the likes list of the post.

Additional Features

• Should be able to like a post by double-clicking it.