[operators.ei] add EmpiricalInterpolatedOperator
[grids.subgrid] rename global_indices to parent_indices
[operators.basic] add ComponentProjection
[la.interfaces] add zeros(), components(), argmax_abs() to VectorArray
[grids.boundaryinfos] add SubGridBoundaryInfo
[operators.constructions] add Concatenation
[operators.constructions] use projected() method if available
[operators.fv] add restricted() to NonlinearAdvectionLaxFriedrichs
[discretizations.nonlinear] small changes
[algorithms.ei] add EI basis generation algorithm
[demos] update burgers demo