Philippe 19/09/2023: OpenACC: PREP_IDEAL_CASE: put some data on GPU (remark: not expected to work on GPU yet)

(work in progress, compilation OK, runs MNH CPU+GPU OK, runs ZSOLVER CPU-only OK)

# Conflicts:
#	src/MNH/advection_uvw.f90
#	src/MNH/advection_uvw_cen.f90
#	src/MNH/advecuvw_4th.f90
#	src/MNH/advecuvw_weno_k.f90
#	src/MNH/dyn_sources.f90
#	src/MNH/gradient_m.f90
#	src/MNH/gradient_u.f90
#	src/MNH/gradient_v.f90
#	src/MNH/gradient_w.f90
#	src/MNH/gravity.f90
#	src/MNH/mode_prandtl.f90
#	src/MNH/ppm.f90
#	src/MNH/prandtl.f90
#	src/MNH/resolved_cloud.f90
#	src/MNH/rmc01.f90
#	src/MNH/shuman.f90
#	src/MNH/tke_eps_sources.f90
#	src/MNH/tridiag_thermo.f90
#	src/MNH/tridiag_w.f90
#	src/MNH/turb.f90
#	src/MNH/turb_hor.f90
#	src/MNH/turb_hor_dyn_corr.f90
#	src/MNH/turb_hor_splt.f90
#	src/MNH/turb_hor_sv_corr.f90
#	src/MNH/turb_hor_thermo_corr.f90
#	src/MNH/turb_hor_thermo_flux.f90
#	src/MNH/turb_hor_tke.f90
#	src/MNH/turb_hor_uw.f90
#	src/MNH/turb_hor_vw.f90
#	src/MNH/turb_ver_dyn_flux.f90
#	src/MNH/turb_ver_sv_corr.f90
#	src/MNH/turb_ver_sv_flux.f90
#	src/MNH/turb_ver_thermo_corr.f90
#	src/MNH/turb_ver_thermo_flux.f90

(cherry picked from commit 59877f0b)