[test][ransnc] update compositional test problem to use general RANS set up

test/freeflow/ransnc/CMakeLists.txt

test/freeflow/ransnc/main.cc

test/freeflow/ransnc/params.input

test/freeflow/ransnc/params_nonisothermal_wallfunction.input

test/freeflow/ransnc/params_wallfunction.input

test/freeflow/ransnc/problem.hh

...references/test_ff_rans2c_kepsilon_twolayer-reference.vtu

...ences/test_ff_rans2c_kepsilon_wallfunctions-reference.vtu

test/references/test_ff_rans2c_komega-reference.vtu

test/references/test_ff_rans2c_lowrekepsilon-reference.vtu

test/references/test_ff_rans2c_oneeq-reference.vtu

test/references/test_ff_rans2c_zeroeq-reference.vtu