classes/buildhistory: improve collection of package info

classes/buildhistory: improve collection of package info

Use a function added to SSTATEPOSTINSTFUNCS and read the necessary
information out of pkgdata, instead of using a function executed
during do_package that reads the data directly. This has two benefits:

* The package info collection will now work when the package content is
  restored from shared state

* Adding/removing the inherit of buildhistory will no longer change the
  do_package signatures and force re-execution of that function for
  every recipe.

Fixes [YOCTO #5358]

(From OE-Core rev: cd7f7efcd5f297d876823b8f579ecefb9542b089)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>