Sidebar - unread button is gone since the upgrade to 3.8.0

Description:

Prior to the upgrade (3.8.0), there was a blue button indicator to show you have unread messages and you need to scroll up/down to see them.

Steps to reproduce:

1. Scroll down in the sidebar
2. Let someone write a message on some channel, out of your view window
3. You have no idea there is a new message there

Expected behavior:

1. The blue button should appear like it used to work in 3.7.2 or some other indicator

Actual behavior:

This is how information is displayed

Server Setup Information:

• Version of Rocket.Chat Server: 3.8.0
• Operating System: Docker image
• Deployment Method: Azure Kubernetes Pod
• Number of Running Instances: 1
• DB Replicaset Oplog: rs0
• NodeJS Version: Unknown - see rocketchat:3.4.1 image.
• MongoDB Version: 4.0.12

Client Setup Information

• Desktop App or Browser Version: Desktop App, 3.0.7

• Operating System: Windows 10

Additional context

• No additional context

Relevant logs:

• No other logs