Harmonize CLI command options

[ahellander]

Is your feature request related to a problem? Please describe. fedn run client, combiner, reducers uses a non-harmonized naming scheme for command options.

For example, client uses -i as short for client_id, while reducer, combiner uses it for port (could be ok, but suboptimal)

reducer uses -i as short for --init, while combiner uses -i . Etc.

A harmonized naming scheme will simplify for users.