Show Gas consumption by default for dry-runs

[cmichi]

The console output should contain the Gas estimate for dry-runs.

Currently:

➜  flipper git:(master) ✗ cargo contract instantiate --suri //Alice --args true                             
      Result Success!
    Contract 5Hgzda4MwEL99i4mz2Szz43txpKafaEsBZu9N9me5LHkfArW
    Reverted false
        Data Bytes([0, 0])
Your instantiate call has not been executed.
To submit the transaction and execute the call on chain, add -x/--execute flag to the command.

Should include:

   Gas limit Weight(ref_time: 323301935, proof_size: 0)

[ascjones]

Closed by #1121