Add contact result properties

[janvonrickenbach]

This is required so that force_elemental_nodal is correctly computed for contact results in pydpf-post. As far as I can see this dictionary is only used to lookup metadata on request and does not impact the available results directly. The scripting name is taken from dataProcessingDoc.html in the dpf core repo.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.38%. Comparing base (d2063fe) to head (99c36fe).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1961      +/-   ##
==========================================
+ Coverage   88.33%   88.38%   +0.04%     
==========================================
  Files          89       89              
  Lines       10225    10225              
==========================================
+ Hits         9032     9037       +5     
+ Misses       1193     1188       -5