Add output formats and print help to `sonalyze top`

[lars-t-hansen]

At the moment, sonalyze top produces human-readable fixed-form output only, and has no -fmt option. Improvements are described in the block comments for the command, notably we should use the standard formatting framework to produce output in all the standard forms and to provide printing help. This command is most similar to the load command and inspiration may be taken from that code, or with luck maybe something can be shared.