Fixes #18901 - fix bottom notification dropdown

fixes #18476 - users have ssh keys

Fixes #18728 - notifications scroll

Fixes #18234 - display correct icon when no unread notifications

--amend

Fixes #18888 - refactor powerStatus

Refs #18804 - move spinner help icons

Fixes #18591 - powerStatus in redux

Fixes #18638 - add sass support to webpack

Fixes #18426 - Add actions to notification entries

This adds support for the notifications to display actions. In case no
actions are provided, the dropdown kebab isn't shown. The actions
possible right now only include GET links.

refs #18464 - rename *.spec.js to *.test.js