In the previous commit, I extended the pull mechanism to support
filtering based on the remote peer.

The goal was to ensure that peers only gossip identities of either
their own organization, or of organizations they are gossiping with.
(Meaning- if A gossips with B identities, the identities that are sent
are either identities of A or of B).

In this commit I hook a filter to the constructor of the identity puller
that extracts the organization of the remote peer, and based on the
organization of the digest (which is the PKI-ID of the identity),
the filter ensures the confidentiality explained above.

I also extended the test of the first commit in the series, to inspect
identities that travel between organizations, to make sure
that the confidentiality rules are preserved.

I also did the following test, to make sure that state transfer between
peers still works:

network_setup.sh: Overided the docker-compose file with docker-compose-no-tls
peer-base/peer-base-no-tls.yaml: I made both options:
      - CORE_PEER_GOSSIP_ORGLEADER=false
      - CORE_PEER_GOSSIP_USELEADERELECTION=false
And in docker-compose-no-tls.yaml I made ONLY peer0 to be ORGLEADER-true

Then I ran network_setup.sh up and it passed, so this proves that
peer2 and peer3 got their blocks from peer0 (or peer1).

Change-Id: Ied4979dd5cfc24ef7b0d1bc092653e9f037a64f2
Signed-off-by: Yacov Manevich <yacovm@il.ibm.com>