YAMBO_ALLOC macro vs function

[sangallidavide]

At present YAMBO_ALLOC is a multi-line macro.

An alternative would be to use a function/subroutine, with an interface.
I understand this is allowed for allocatable variables (see discussion here https://stackoverflow.com/questions/13058743/how-to-pass-allocatable-arrays-to-subroutines-in-fortran which is 12 years old)