Make changes to not expose the aliases "gin", "gsv", "sasv" and "spsv" in Unix platforms.
Also refactored aliases related tests and added new tests covering the complete list of built-in aliases/cmdlets.
This restructuring moves tests to a directory name which matches the module
in which the cmdlet resides which should improve the discoverability of a
specific test.
For tests which are not about cmdlets in a module, new directories have been
created to make those tests easier to find as well
Ilya