FluvioAdmin.all_topics() output MetadataTopicSpec should return full range of topic config info

[digikata]

https://infinyon.github.io/fluvio-client-python/fluvio.html#MetadataTopicSpec output by calls like https://infinyon.github.io/fluvio-client-python/fluvio.html#FluvioAdmin.all_topics should also expand. It would be nice to could also simplfy this so input and output TopicSpec are the same (but this isn't a hard requirement)

Originally posted by @digikata in #527