Improve shards_local:info/1,2 to be compliant with ETS functions

[cabol]

The idea is to return information about the shards as well, like number of shards, a list of shards tables. etc. So instead of return only a list with the info for each shard, return a mixed tuple list with the regular ETS info and additionally with the shards info. For items like memory and size it would be necessary to sum all shards values.