feature(metrics): Add database metrics in human readable form

[oxarbitrage]

In #8336 we added metrics for the database total size, memory size and so on.

For example a default output looks of this addition when starting zeba is as:

2024-03-26T11:17:33.249322Z  INFO {zebrad="d3af910" net="Main"}: zebra_state::service::finalized_state::disk_db: Total Database Disk Size: 36496028741 bytes
2024-03-26T11:17:33.249421Z  INFO {zebrad="d3af910" net="Main"}: zebra_state::service::finalized_state::disk_db: Total Live Data Disk Size: 18031326069 bytes
2024-03-26T11:17:33.249435Z  INFO {zebrad="d3af910" net="Main"}: zebra_state::service::finalized_state::disk_db: Total Database Memory Size: 49152 bytes

I think we can group together the 3 lines into 1 and also convert the bytes to human readable form, there are a few crates around to do this, for example:

https://crates.io/crates/human_bytes
https://crates.io/crates/humanize-bytes