Casper-client [get-transaction should allow returning both transactions and legacy deploys]

[RBYGLLS]

Component: casper-client
Description: Right now casper-client get-transaction receives the Digest corresponding with the transaction as a parameter. The command assumes that the provided Digest belongs to a V1 transaction but get-transaction should allow users to also retrieve old style deploys. This is because the new Transaction is actually a versioning wrapper that can understand both legacy deploys and new style v1 transactions.
The ask is to add a new command line parameter to casper-client get-transaction that allows users to specify if the provided digest Digest resolves to a V1 transaction hash or a legacy Deploy hash. (e.g. casper-client get-transaction -d 0xabc232 retrieves a transactions by TransactionHash::Deploy(DeployHash(0xabc232)) and `casper-client get-transaction -v1 0xabc232 retrieves a transactions by TransactionHash::V1(TransactionV1Hash(0xabc232)) )
Release: 2.0