package_manager.py: Add extract() method for opkg and dpkg
Sometimes it is needed to have the content of a package outside
the recipe context. This new method extract the content of an
IPK/DEB file to a tmpdir, without actually installing the package.
A new OpkgDpkgPM class was added to share the code for opkg and dpkg.
There were need some changes to opkg_query() in order to use it
with apt-cache output. Also set default values to avoid UnboundLocalError
[YOCTO #9569]
Signed-off-by: Mariano Lopez <mariano.lopez@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
