Add class NonMatching::FEValues

Add class NonMatching::FEValues

This class makes it easier to assemble cut finite element methods, when
the domain is described by a level set function. In the same way as
hp::FEValues, NonMatching::FEValues generates dealii::FEValues like
objects, but where these contain quadrature rules to integrate over the
3 different regions of the cell that are defined by the sign of the
level set function.