Add Job for new peers to join channels with the help of ledger snapshots

[runitmisra]

If administrators decide to add new peers to established channels, it can take a long time for a peer to catch up to the current ledger height and build the ledger from world state. To make this process easier, we can use Snapshots to capture the minimum required data for the peer to join the channel without it having to do the long process of building the ledger from world state.

Detailed info of this feature can be found here: https://hyperledger-fabric.readthedocs.io/en/latest/peer_ledger_snapshot.html

Create a Job that can take a snapshot of the existing ledger in a channel and can add a peer to the channel using that snapshot (This can be a separate job)

[tittuvarghese]

Need to do the following,

1. Job to take snapshot and store.
2. Support for snapshot path and flags to join to the channel from snapshot. (Change in existing join channel job)
3. Cleanup policy to maintain only Last N snapshots.