Merge branch 'cleanup/rename-ff-test-folders' into 'next'

test/freeflow/CMakeLists.txt

test/freeflow/navierstokes/CMakeLists.txt

test/freeflow/navierstokes/angelitestproblem.hh

test/freeflow/navierstokes/channeltestproblem.hh

test/freeflow/navierstokes/closedsystemtestproblem.hh

test/freeflow/navierstokes/doneatestproblem.hh

test/freeflow/navierstokes/kovasznaytestproblem.hh

test/freeflow/navierstokes/test_angeli.cc

test/freeflow/navierstokes/test_channel.cc

test/freeflow/navierstokes/test_channel_navierstokes.input

test/freeflow/navierstokes/test_channel_stokes.input

...eflow/navierstokes/test_channel_stokesni_conduction.input

...eflow/navierstokes/test_channel_stokesni_convection.input

test/freeflow/navierstokes/test_closedsystem.cc

test/freeflow/navierstokes/test_donea.cc

test/freeflow/navierstokes/test_hydrostaticpressure.input

test/freeflow/navierstokes/test_kovasznay.cc

test/freeflow/navierstokes/test_liddrivencavity.input

test/freeflow/navierstokes/test_navierstokes_angeli.input

test/freeflow/navierstokes/test_navierstokes_kovasznay.input