New scenario FAINTER

This new SearchCal scenario FAINTER (== SearchFTT) will consist in:
- primary request in 2MASS (like former FAINT scenario) to get candidates (JHK fluxes)
- secondary requests: ASCC ... but mainly GAIA !

This scenario will use the new approach (G -> V conversion) to estimate stellar diameters on million stars (470e6 2MASS x 1.8e9 GAIA DR3)