feat(global header): Add global actions with animations (#3008)

* feat(global-header): componentize parts of global header and add new global actions component

* Begin docs

* Begin docs

* Add documentation and tests

* Revert export

* Update snapshots

* update snapshots

* Fix lint and tests

* Add annotations and updated tests

* Fix typos and deconstructed props

* Add rem function to px values, add copy regarding unread notifications

* Fix lint

* Change token ref to brand, update tests

* Add some documentation around notifications

* Add favorites popover and task menu

* Update snapshots

* Update menus component to take custom icon

* Lint

* Update snapshots

* Update snapshots

* Update snapshots

* Update snapshots

* Add accessibility note to new notifications

Author: brandonferrua