feature request: reorganize equo preservedlibs normal and verbose modes

[unode]

The command equo preservedlibs list lists only the libs that have been preserved.
Adding -v makes the same output also inform which packages are causing libs to be preserved. Personally I wouldn't expect to find said output under a --verbose flag.

As per #41 (comment) defaulting to -v is potentially more useful.

Alternatively and from a UI point of view, one could also argue that -v answers a different question in which case it might make sense to split these to different commands. e.g. equo preserved libs list and equo preserved packages list.