[dashboard] storage: record size by column family
[dashboard] storage: record size by column family

To observe record sizes in each data set, reveal potential changes of that on occasions like when new type of events are invented, data serialization change, etc.

libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core