libandroidfw: add resource ID iterator

Add an iterator to LoadedPackage which allows the caller to iterate over
the resource IDs in the package. This will be used by idmap when
constructing the idmap file.

Bug: 78815803
Test: make libandroidfw_tests
Change-Id: Ia47daa21390d67ea2ef3665e88eb407837c4764f
3 files changed