[Feature request] Support Tera prefix (and maybe even Peta and Exa) with `-U` and `-u`

[xtaran]

Hi,

nload currently shows me on a host with just two weeks of uptime:

Ttl: 37505.16 GByte

This should better be displayed like this:

Ttl: 37.50 TByte

Currently -U only supports unit prefixes up to G for "Giga". Adding T for Tera (and maybe even already P for Peta and E for Exa) would be helpful.

And given that there are off-the-shelf 400 GBit/s network interfaces out there, supporting the Tera unit prefix for -u starts to make sense as well.

[Low-power]

Hello.

Units tebibit, tebibyte, pebibit, pebibyte, terabit, terabyte, petabit and petabyte has been added in #6.

Here's an example of nload -u Hi on my machine: