Enhancement: Explain RACF return and reason codes

**Is your feature request related to a problem? Please describe.**
RACFu should be able to provides the explanations for RACF return and reason codes rather than requiring users to look them up in the documentation.

**Describe the solution you'd like**
Have RACFu provide explanations with RACF return and reason codes.

**Describe alternatives you've considered**
N/A

**Additional context**
N/A
