base1: Clean up and strenghten format_bytes_per_sec test
base1: Clean up and strenghten format_bytes_per_sec test

Move to a declarative style by adding all strictEqual() checks to the
`checks` list. Add the unit and options arguments, drop the
corresponding redundant code, and add a few missing test cases.

cockpit-project/cockpit,cockpit-project/cockpit,martinpitt/cockpit,martinpitt/cockpit,mvollmer/cockpit,martinpitt/cockpit,cockpit-project/cockpit,mvollmer/cockpit,martinpitt/cockpit,martinpitt/cockpit,cockpit-project/cockpit,mvollmer/cockpit,mvollmer/cockpit,cockpit-project/cockpit,mvollmer/cockpit