nbc: rework the way to add arrays to clean up

[hppritcha]

Turns out that in the course of working on PR #13280 , it was discovered that auxiliary arrays associated with a non-blocking/persistent collective requests were not in fact being cleaned up upon either completion of the non-blocking request or freeing of the persistent request except for instances where the 'c' interface detected certain cases for the arguments (in particular user-defined data types).

So all the additions to the fortran code to cleanup temporary arrays needed, for example, when default integer type does not map to 'c' int, was not actually doing anything in the general case.

This PR also hides the way the auxiliary array info is associated with the request rather than having the current array of pointers in the nbc request exposed in many different places.

This PR also fixes up some problems found with handling of some of the arrays within the f90/f08 code as well as suppressing some compiler warnings.