Allow input mask configuration

Users must be able to inform which values of the input mask they want to use as not clear.
e.g. 
A user wants to define 4, 5 and 6 on Sentinel 2 cloud mask (SCL) as clear values, while other user wants to use 4, 5, 6, 7 and 10 as clear.
Note: The nodata of this mask can be different from input data