Evaluate just-in-time mapping feature of preCICE 3.2.0 to replace custom interpolation

The FEniCS adapter performs its own interpolation [here](https://github.com/precice/fenics-adapter/blob/394664dd720bd8d4e5a5f50aa7cdb1e5c7af1e95/fenicsprecice/expression_core.py#L172). With the new just-in-time mapping feature (https://github.com/precice/precice/pull/2099) we could remove this interpolation and directly use the interpolation in preCICE.