Simplify function names in unit test

[jphickey]

The function names in the unit test code are absurdly verbose. Some of these unit test function names are 150+ characters in length (exceeding the clang-format line length limit on their own!).

This could be considered coding style, but this is so excessive that it warrants pruning them all back - Note that for portability, symbol names should ideally be kept under 32 significant characters. This is per ISO STD C9899 section 5.2.4.1 - This says that an implementation is only required to recognize 31 significant chars on an external symbol name, or 63 on a local symbol name. The fact that this goes so far beyond the c99-specified limits is a good reason to fix it.

Example: https://github.com/nasa/CF/blob/a894069439316ef89ad7751f3a03036930158a07/unit-test/cf_cfdp_s_tests.c#L1224

Descriptive content on what the test is supposed to do belongs in comments, not within the function name itself.