Implement method to make a request to the tarball
url. The response is written in the folder,
uncompressed and checked for its integraty and
then hashes are computed

Introduce hookpoint cleanup_artifact() which
could be overridden to delete unnecessary binary
files from the downloaded tarball.

extract_metadata() method can be overridden to
parse over files present in downloaded pakage
version to obtain metadata. This metadata can be
added to the the existing metadata available for a
package version, which further will be used to
build revision.

Depends on D1810