Add "Messages behind" for Topics within Consumer group profile

[armenuikafka]

Describe the bug Add "Messages behind" for Topics within Consumer group profile

Set up https://www.kafka-ui.provectus.io/

Steps to Reproduce

Steps to reproduce the behavior:

1. Navigate to Consumer group profile
2. Check the linked Topics list

Expected behavior Should be displayed "Messages behind" for each Topic

Screenshots

[Haarolean]

would be nice if that's possible to implement

[winnie-chiu]

I'd like to work on this.