Now each file in zip archive requires 2 or 3 calls to db:
1. initialize blob instanse, 2.(optional) upload data if
database store is used, 3. activate blob instance
So, for 100 files there are 300 requests, and complexity
is O(n).
With this commit we perform requests for all files in batch
mode: 1. initialize all blob instances, 2.(optional) upload
all data if database store is used, 3.activate all blob
instances.
So, for any number of files in archive there will be only 2 or
3 requests to db. Complexity is O(1).
Change-Id: I87ea9d1f87dc6519956808a1d1e764f16e6dc611