[FEATURE_REQUEST] static width and units for the network#speed module

[ipuustin]

Currently the network#speed module has the bandwidth values length changing -- would it be possible to add padding to the values to prevent distracting resizing?

For example, go from △ 4.0B/s ▽ 128.0B/s to △ 4.0B/s ▽ 128.0B/s

While at it, could we configure the lower and upper limit of the units used? I would like to have a kB (or MB) as the base unit to make the network traffic speed recognizable by a glance. So go from △ 4.0B/s ▽ 128.0B/s to △ 0.0kB/s ▽ 0.1kB/s.