Hides tooltip on discussion toggle button when clicking

## What does this MR do?

Hides the tooltip when clicking the discussion toggle button.

Rather than triggering the tooltip to hide we trigger blur. This is because of how _amazing_ Bootstraps tooltips are. They are shown also on focus so if we trigger the tooltip to hide & then mouseover the button again the tooltip still shows. 

## What are the relevant issue numbers?

Closes #20750

See merge request !6303