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.
To provide more control of the summary as part of details.
To support, added a way to ignore elements during import DOM, allowing
up to read summaries when parsing details without duplicate nodes
involved.
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.
