PR to master: Small changes to run surface elasticity simulations

These are a bunch of commits, mainly to add printing or post processing of variables needed for the surface energy simulations. To be merged from master into the periodic relaxation branch. Commits: 27f629be ba59982b cad721a6 23a0b59d 34dbbc5e 1abe0926 7989365e f39bf78f 24e58c6e 9f289485 94ee637a b4556f92 bd36953d cf72efe4 6d347bbe 03bd975f 23815224 5af5bb79 e5e0b45f

Open tasks:

• Create merge request and cherry-pick commits
• 3/2 factor for kinetic energy
• Check if automatic tests possible
• Review