tests/functional: add a generalized archive_extract

tests/functional: add a generalized archive_extract

There are many types of archives that the tests deal with. Provide
a generalized 'archive_extract' that can detect the format and
delegate to the appropriate helper for extraction. This ensures
that all archive extraction code follows the same design pattern.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20241217155953.3950506-22-berrange@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>