closes https://github.com/TryGhost/Ghost/issues/14146
refs https://github.com/TryGhost/Admin/pull/2251
- an action rename was missed when converting the toolbar component to native class syntax
- added test for the h3 toolbar button working
- fixed `<KoenigEditor>` not assigning the test property that gives tests access to the underlying mobiledoc `editor` instance
no issue
- upgrade to latest `ember-source` and related dependencies including `ember-cli`
- upgrade to latest `ember-mocha` and modern ember testing setup
- https://github.com/emberjs/rfcs/blob/master/text/0268-acceptance-testing-refactor.md
- switch from using global acceptance test helpers and `native-dom-helpers` to using the new `ember-test-helpers` methods
- use [`chai-dom`](https://github.com/nathanboktae/chai-dom) assertions where in some places (still a lot of places in the tests that could use these)
- pin `ember-in-viewport` to 3.0.x to work around incompatibilities between different versions used in `ember-light-table`, `ember-infinity`, and `ember-sticky-element`
- incompatibilities manifested as "Invalid value used as weak map key" errors thrown when using `ember-light-table` (subscribers screen)
- pin `ember-power-datepicker` to unreleased version that contains a move from global acceptance test helpers to modern test helpers
refs https://github.com/TryGhost/Ghost/issues/9311
Koenig is being fully rebooted, first port of call is to focus on getting the rich-text only aspect of mobiledoc-kit working with our popup toolbar.
- renames old koenig implementation (used for reference, will eventually be deleted)
- new `{{koenig-editor}}` mobiledoc-kit component implementation based on ember-mobiledoc-editor
- markdown text expansions
- new `{{gh-koenig-edtor}}` that wraps our title+editor and handles keyboard navigation between the two
- clicks below content will focus the editor
- new `{{koenig-toolbar}}` component for the popup formatting toolbar with improved behaviour and simplified code
