[test] Add freeflow label to multidomain freeflow tests

test/multidomain/boundary/stokesdarcy/1p2c_1p2c/diffusionlawcomparison/CMakeLists.txt

 add_input_file_links()
 
 dune_add_test(NAME test_md_boundary_darcy1p2c_stokes1p2c_maxwellstefan
-              LABELS multidomain
+              LABELS multidomain freeflow
               SOURCES main.cc
               CMAKE_GUARD HAVE_UMFPACK
               COMPILE_DEFINITIONS DIFFUSIONTYPE=MaxwellStefansLaw<TypeTag>
@@ -15,7 +15,7 @@ dune_add_test(NAME test_md_boundary_darcy1p2c_stokes1p2c_maxwellstefan
                             --command "${CMAKE_CURRENT_BINARY_DIR}/test_md_boundary_darcy1p2c_stokes1p2c_maxwellstefan params.input")
 
 dune_add_test(NAME test_md_boundary_darcy1p2c_stokes1p2c_fickslaw
-              LABELS multidomain
+              LABELS multidomain freeflow
               SOURCES main.cc
               CMAKE_GUARD HAVE_UMFPACK
               COMPILE_DEFINITIONS DIFFUSIONTYPE=FicksLaw<TypeTag>

test/multidomain/boundary/stokesdarcy/1p2c_1p2c/horizontalflow/CMakeLists.txt

 add_input_file_links()
 
 dune_add_test(NAME test_md_boundary_darcy1p2c_stokes1p2c_horizontal
-              LABELS multidomain
+              LABELS multidomain freeflow
              SOURCES main.cc
              CMAKE_GUARD HAVE_UMFPACK
              COMMAND ${CMAKE_SOURCE_DIR}/bin/testing/runtest.py

test/multidomain/boundary/stokesdarcy/1p2c_1p2c/verticalflow/CMakeLists.txt

@@ -3,7 +3,7 @@ add_input_file_links()
 add_executable(test_md_boundary_darcy1p2c_stokes1p2c_vertical EXCLUDE_FROM_ALL main.cc)
 
 dune_add_test(NAME test_md_boundary_darcy1p2c_stokes1p2c_vertical_diffusion
-              LABELS multidomain
+              LABELS multidomain freeflow
               TARGET test_md_boundary_darcy1p2c_stokes1p2c_vertical
               CMAKE_GUARD HAVE_UMFPACK
               COMMAND ${CMAKE_SOURCE_DIR}/bin/testing/runtest.py
@@ -17,7 +17,7 @@ dune_add_test(NAME test_md_boundary_darcy1p2c_stokes1p2c_vertical_diffusion
                              -Vtk.OutputName test_md_boundary_darcy1p2c_stokes1p2c_vertical_diffusion")
 
 dune_add_test(NAME test_md_boundary_darcy1p2c_stokes1p2c_vertical_advection
-              LABELS multidomain
+              LABELS multidomain freeflow
               TARGET test_md_boundary_darcy1p2c_stokes1p2c_vertical
               CMAKE_GUARD HAVE_UMFPACK
               COMMAND ${CMAKE_SOURCE_DIR}/bin/testing/runtest.py

test/multidomain/boundary/stokesdarcy/1p2c_2p2c/CMakeLists.txt

 add_input_file_links()
 
 dune_add_test(NAME test_md_boundary_darcy2p2c_stokes1p2c_horizontal
-              LABELS multidomain
+              LABELS multidomain freeflow
               SOURCES main.cc
               CMAKE_GUARD HAVE_UMFPACK
               COMMAND ${CMAKE_SOURCE_DIR}/bin/testing/runtest.py
@@ -15,7 +15,7 @@ dune_add_test(NAME test_md_boundary_darcy2p2c_stokes1p2c_horizontal
                              -Vtk.OutputName test_md_boundary_darcy2p2c_stokes1p2c_horizontal")
 
 dune_add_test(NAME test_md_boundary_darcy2p2cni_stokes1p2cni_horizontal
-              LABELS multidomain
+              LABELS multidomain freeflow
               SOURCES main.cc
               COMPILE_DEFINITIONS NONISOTHERMAL=1
               CMAKE_GUARD HAVE_UMFPACK

test/multidomain/boundary/stokesdarcy/1p3c_1p3c/CMakeLists.txt

 add_input_file_links()
 
 dune_add_test(NAME test_md_boundary_darcy1p3c_stokes1p3c_horizontal
-              LABELS multidomain
+              LABELS multidomain freeflow
               SOURCES main.cc
               CMAKE_GUARD HAVE_UMFPACK
               COMMAND ${CMAKE_SOURCE_DIR}/bin/testing/runtest.py

test/multidomain/boundary/stokesdarcy/1p_1p/horizontalflow/CMakeLists.txt

 add_input_file_links()
 
 dune_add_test(NAME test_md_boundary_darcy1p_stokes1p_horizontal
-              LABELS multidomain
+              LABELS multidomain freeflow
               SOURCES main.cc
               CMAKE_GUARD HAVE_UMFPACK
               COMMAND ${CMAKE_SOURCE_DIR}/bin/testing/runtest.py

test/multidomain/boundary/stokesdarcy/1p_1p/verticalflow/CMakeLists.txt

 add_input_file_links()
 
 dune_add_test(NAME test_md_boundary_darcy1p_stokes1p_vertical
-              LABELS multidomain
+              LABELS multidomain freeflow
               SOURCES main.cc
               CMAKE_GUARD HAVE_UMFPACK
               COMMAND ${CMAKE_SOURCE_DIR}/bin/testing/runtest.py

test/multidomain/boundary/stokesdarcy/1p_2p/CMakeLists.txt

 add_input_file_links()
 
 dune_add_test(NAME test_md_boundary_darcy2p_stokes1p_vertical
-              LABELS multidomain
+              LABELS multidomain freeflow
               SOURCES main.cc
               CMAKE_GUARD HAVE_UMFPACK
               COMMAND ${CMAKE_SOURCE_DIR}/bin/testing/runtest.py