Quentin 07/05/2024: bugfix for use of CBL_HEIGHT_DEF=FRI: bl_depth_diag can be...

Quentin 07/05/2024: bugfix for use of CBL_HEIGHT_DEF=FRI: bl_depth_diag can be called with arrays in the full vertical dimensions
or the les vertical dimensions. The 1D version was also wrong. The FRI option was missing in the user guide (option forgotten since many years)