Add typedef for OSAL status codes

[jphickey]

Is your feature request related to a problem? Please describe.
In the recent versions of CFE, a typedef (CFE_Status_t) is added and used for the return type on any function that returns a CFE status code, while OSAL continues to use a bare int32 return type.

Although the type does need to be integer in nature (to maintain semantics of equality checks, etc), the typedef does still serve a useful purpose, in that it implies behavioral characteristics of the function i.e. that its return value should be checked against the set of defined status values for that module where certain values have defined meaning - as opposed to a generic number.

Describe the solution you'd like
OSAL should define an OS_Status_t (which can be a typedef to int32) and prototypes of functions returning a status value should be updated to OS_Status_t to more clearly indicate when the return value should be compared against the set of constants defined in osapi-error.h.

Describe alternatives you've considered
Leave as int32 (inconsistent with CFE).

Additional context
In particular, having a separate type and macros helps identify cases where improper or incomplete type conversions are done, for instance see nasa/cFE#1599

Requester Info
Joseph Hickey, Vantage Systems, Inc.

[skliper]

Note the typedef was added in #1112, I guess this issue is still open to actually use it everywhere. For example:

osal/src/os/inc/osapi-error.h

Line 167 in acb88ca

int32 OS_GetErrorName(int32 error_num, os_err_name_t *err_name);