Slack Notification: interactive message, update progress of build

Description of the feature request

For the Slack step, can we have like 60seconds interval, which would update progress of build in Slack message? Like on build start, it would send notification to Slack, later it would update every minute, to see the progress. It should leverage logic from bitrise frontend, which estimates the progress of each build.

Use case / for what or how I would use it

I just wanna let other team members to see where is the build currently. Especially when builds can take up to 45 minutes.