extract PackageRoot to handle common tasks on extracted packages,
such as translating between absolute and package-relative paths,
and enumerating contents
test plan:
- ensure the package attached to the ticket is handled correctly
- regression test course copies and Canvas cartridge imports
refs ADMIN-528
Change-Id: I76b67076a48c8acedcde523d46aac8e2ccef76d0
Reviewed-on: https://gerrit.instructure.com/132389
Tested-by: Jenkins
Reviewed-by: James Williams <jamesw@instructure.com>
QA-Review: Deepeeca Soundarrajan <dsoundarrajan@instructure.com>
Product-Review: Jeremy Stanley <jeremy@instructure.com>
Jeremy Stanley