Implement Shard ID Flag for CLI

[terencechain]

We are missing Shard ID from user input. Shard ID will be used for services like p2p, observer and proposer. P2p service needs shard ID to know which network to start p2pServer. Proposer service needs shard ID to know which shard to listen incoming transactions, and package transactions into collations and submit to the SMC.

The geth command will look like this for a proposer to propose collation in shard 0:
geth sharding --actor "proposer" --shardID 0 --datadir ../datadir --password password.txt --networkid 12345

The geth command will look like this for an observer to listen in shard 100:
geth sharding --actor "observer" --shardID 100 --datadir ../datadir --password password.txt --networkid 12345

[terencechain]

Closed via #169