Also:
- Added svg loading support (dummy stub) for jest.
- Updated headless test case due to node changes.
- Split out editor change detected to where appropriate.
- Added functions to help with testing, like mocking our context.
- Updated toolbar to match existing editor, including dynamic RTL/LTR
controls.
- Updated text node handling to not include spans and extra classes when
not needed. Added & update tests to cover.
Imported at 0.17.1, Modified to work in-app.
Added & configured test dependancies.
Tests need to be altered to avoid using non-included deps including
react dependancies.
