DuoChat adapt namespace of custom styles.
For the sake of custom styles there are some occurences of .gl-drawer
to apply custom styles to DuoChat in our Codebase.
With this GitLab UI-MR: gitlab-ui!4034 (merged)
Duo-chat will no longer lean on gl-drawer styles but rather use it's own namespace. Before we update the GitLab UI version including this refactoring we have to adapt these custom styles.