[linearelliptic.discretizations.swipdg] fixed preprocessor directives
[linearelliptic.discretizations.block-swipdg] fixed include path
[linearelliptic.discretizations.swipdg] fixed typo
[linearelliptic.discreteproblem] update multiscale grid visualization
[linearelliptic.discretizations.block-swipdg] implemented estimator
[tests.linearelliptic-swipdg] do not use

DUNE_HDD_LINEARELLIPTIC_DISCRETIZATIONS_SWIPDG_ESTIMATOR_ALTERNATE_SUMMATION
[examples.linearelliptic.block-swipdg] define

DUNE_GRID_MULTISCALE_PROVIDER_CUBE_DISABLE_CHECKS
[cmake] disabled everything exect the one test and example of interest