naming for surface latent/sensible heat fluxes in model

Hi,

A more clear naming in terms of surface heat fluxes is needed to avoid confusion. For example, I noticed that in atm diagnostics the term "hflsd" is surface latent heat, the NET heat fluxes and not only the downward component. Which corresponds to "hfls" of eraint, not the 'hflsd'. This can be a source of error in fluxes when comparing model output with eraint. The same comment applies to 'hfssd' and 'hfss' which is the sensible heat fluxes. @pabretonniere @cprodhomme @obellprat @mmenegoz @nevensf @fmassonnet and please further tag people who use surface fluxes in case they need to correct it.

Cheers Eleftheria