Use npm workspaces (#2476)

* Use npm workspaces

* Unused ora dependency

* Update karma.conf to include new search path

* Remove further package-locks

* Switch preact testing from enzyme to testing-library

lockfilemageddon updated cheerio from rc.10 to final. This included a
breaking change which enzyme hasn't been updated to handle, but seeing
as enzyme is no longer maintained....let's just throw our toys out the
pram and switch to testing library

* Run npm dedupe

* re-run test

Author: mrginglymus