Left-clicking the delete button on the avatar in the My Account screen should also delete the avatar image from the S3 bucket

Currently, all this does is the following:

1. Update the user object to set the avatarUrl field to ''
2. Remove the user-avatar-url token from the browser's LocalStorage
3. Remove the image from the image list state associated with the avatar UI component

It does not actually delete the image on the backend. It should also make an API call to delete the image from the S3 bucket.