By Evalf, and other Nutils contributors

officialFSIbenchmark problem

This is a monolythic ALE (Arbitrary Lagrangian Eulerian) implementation of the fluid-structure interaction benchmark defined in 2006 by Turek and Hron. The implementation covers all fluid dynamics tests CFD1, CFD2 and CFD3, all structural tests CSM1, CSM2 and CSM3, and all interaction tests FSI1, FSI2 and FSI3, as well as freely defined variants thereof.