Function to recognize multiarch tuples in directory names

[nightlark]

Matching include directories accurately requires being able to distinguish directories for different multiarch tuples from other arbitrary directory names.

There are also a handful of cases where it will be needed to pick to correct package name after normalizing a shared library name, such as libusb-1.0.so (normalized as libusb.so):

Collision libusb.so from libusb-1.0.so with matching package names
Original package names: [("libdevel/libusb-1.0-0-dev", "usr/lib/x86_64-linux-gnu/libusb-1.0.so")]
Normalized package names: [("universe/text/calibre-bin", "usr/lib/calibre/calibre/plugins/libusb.so"), ("libdevel/libusb-dev", "usr/lib/x86_64-linux-gnu/libusb.so")]

See #5 (comment) for more examples.