Add option unit to get_size: IEC or metric

e.g.:
IEC for disks
metric for RAM
3 jobs for get_size_IEC_vs_metric in 1 minute and 33 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Validate
passed #214556
grid5000-docker
validate-data

00:00:51

 
  Generate
passed #214557
grid5000-docker
generate-reference-api

00:00:35

 
  Deploy
passed #214558
grid5000-shell
deploy

00:00:06