Update reporting of the asymmetric unit contents to deal with multiple crystals: 1. In Crystal class: add methods for handling ASU data (nmols in ASU and    solvent fraction) 2. Feed ASU data to Crystal objects in Xia2run.__populate() method 3. Update ASU contents reporting in "Crystallographic parameters".
Update reporting of the asymmetric unit contents to deal with multiple
crystals:
1. In Crystal class: add methods for handling ASU data (nmols in ASU and
   solvent fraction)
2. Feed ASU data to Crystal objects in Xia2run.__populate() method
3. Update ASU contents reporting in "Crystallographic parameters".

xia2/xia2,xia2/xia2