Code in lists could throw error on parse due to inner <code> tag being
parsed but not actually used within a <pre>, so this updates the
importDOM to disregard childdren for code blocks.
This also improves the invariant implementation to not be so
dev/debugger based, and to include vars in the output.
- 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.
