Move workers and threading outside @openhps/core

[Maximvdw]

Threading currently takes up a lot of space for the dependencies. In the future we should move the threading aspect outside @openhps/core (which makes sense since the worker file would already be an 'external' file).

We plan to do this once we reach 300KB for the minified file size of @openhps/core.

[Maximvdw]

With our aim for using OpenHPS on embedded systems, this requirement has become more urgent. However, we currently have an openhps-core-lite.min.js file that is compiled that removes the threading possibilities.