Lammps.js v1.2.0

Closes: #16 Add the ability to control the simulation from JS (#24)

* Add the ability to control the simulation from JS

* Remove unnecessary #ifdef __EMSCRIPTEN__

* Move all generate files into dist

* Improve and fix CI

* Remove js file

* Simple updated readme

* Clean up the new interface a bit

* fix js async callbacks for run/minimize + compute scalar sync, add tests

* Rename async method

* Change example to control simulation speed only through the async method

* Bumped version

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Co-authored-by: Anders Hafreager <anders.hafreager@cognite.com>