Merge branch 'feature/cmake-python-overhaul' into 'master'

.gitlab-ci.yml

CMakeLists.txt

bin/CMakeLists.txt

bin/dunecontrol

bin/dunepackaging.py

bin/rmgenerated.py

bin/setup-dunepy.py

cmake/modules/CMakeLists.txt

cmake/modules/DuneExecuteProcess.cmake

cmake/modules/DuneMacros.cmake

cmake/modules/DunePythonCommonMacros.cmake

cmake/modules/DunePythonDeprecations.cmake

cmake/modules/DunePythonInstallPackage.cmake

cmake/modules/DunePythonMacros.cmake

cmake/modules/DunePythonTestCommand.cmake

cmake/modules/DunePythonVirtualenv.cmake

cmake/pkg/dune-common-config.cmake.in

cmake/scripts/CMakeLists.txt

cmake/scripts/WritePythonCMakeMetadata.cmake

cmake/scripts/checkvenvconf.py