extend cohesive-frictional model

For consistency this MR should be merged before !974 (merged) (some commits were cherry-picked from there)

• use signed normal force to define max moments
• introduce a cohesion-like constant term for max values of the torques (not just something proportional to normal force), now the cohesive interactions can break in twist/rolling
• WARN_ONCE when twisting/rolling are not both elastic or both elastic-plastic, or other possible inconsistencies that may occur when interaction properties are modified in python scripts
• reorganize the code + smallfixes
• separate functions to 1/ compute trial elastic forces/torques and, 2/ check plasticity/failure
• helper function setCohesion (true/false) to make cohesion assignement more flexible and user friendly