Merge branch 'diff-comments-toggle-tooltip-hide' into 'master'

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

CHANGELOG

@@ -38,6 +38,7 @@ v 8.12.0 (unreleased)
   - Fix bug where pagination is still displayed despite all todos marked as done (ClemMakesApps)
   - Request only the LDAP attributes we need !6187
   - Center build stage columns in pipeline overview (ClemMakesApps)
+  - Fix bug with tooltip not hiding on discussion toggle button
   - Rename behaviour to behavior in bug issue template for consistency (ClemMakesApps)
   - Fix bug stopping issue description being scrollable after selecting issue template
   - Remove suggested colors hover underline (ClemMakesApps)

app/assets/javascripts/application.js

@@ -251,6 +251,7 @@
       } else {
         notesHolders.hide();
       }
+      $this.trigger('blur');
       return e.preventDefault();
     });
     $document.off("click", '.js-confirm-danger');