1) Add in support to get only VarStoreId = 1 from Multiple VarStores.

1) Add in support to get only VarStoreId = 1 from Multiple VarStores.
2) Remove ThunkIfrSupportLib.h
3) Update some comments.
4) Add GetAttributesOfFirstFormSet to scan form package to read formset title, class info.
5) Clean up function related to package registration code.
6) Clean up RemovePackNotify

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@5705 6f19259b-4bc3-4df7-8a09-765794883524