Browse files outside of scanned folders

At the moment, the file browsing functionality, called Music Library, has an awkward limitation, that it only exposes folders in the list of scanned locations.

In fact, both the current name and operation of this feature are worth discussing.

A more general and typical design supports access by directory browsing to arbitrary locations on the local network or system media. This general browsing feature contrasts to a different style of access, normally referred to as a library, to media in specific locations designated for scanning, and accessible through a view organized by metadata tags, such as artist and genre.

Ultimately, the naming is not the important question, as unconventional naming is at worst a mild inconvenience. Rather, support for browsing arbitrary locations, independent of whether they had been designated for scanning, would be a deeply valuable feature.