NJOY modernisation and GNDS support in scion

The NJOY modernisation strategy in which the required format components (for ENDF and ACE) were developed first is moving to the next stage in which development of processing components has started. The first among there is scion, modern NJOY's component for the interpretation, linearisation, integration and differentiation. The current state of this new component already allows us to perform some diagnostics on the methods used in NJOY2016 for the processing of ACE files. In addition, to providing the basic operations that will be used in various processing modules, scion will also provide a format agnostic data interface capable of reading in and writing out data from various evaluated nuclear data format including ENDF and GNDS. https://github.com/njoy/scion https://github.com/njoy/scion/blob/feature/examples-1/python/examples/h1-elastic-angular-distribution.ipynb https://github.com/njoy/scion/blob/feature/examples-1/python/examples/h1-capture-linearisation.ipynb