Properly localize numbers

[martinpitt]

We currently don't properly localize numbers with thousands or decimal separators. E. g. when switching language to German, the network page shows:

and the storage page shows:

Our localization API does not have a function for formatting numbers according to the current locale, but I figure we don't really need one: Our code could just use

>> n = 1234.56
>> n.toLocaleString(cockpit.language)
"1.234,56"

If we add an API to base, we need some fallback anyway as we might run against an older cockpit-bridge package (like on RHEL or with containers).

[allisonkarlitskaya]

cockpit.format_number() in already contains this comment:

    /* TODO: Make the decimal separator translatable */

    /* We show 3 digits of precison but avoid scientific notation.
     * We also show integers without digits after the comma.
     */

Would implementing this change there be considered an API break in your opinion? If not, do we basically need to go all over the place, changing each separate location?

[martinpitt]

format_number() is explicitly for turning a Number into a humanly readable string, so respecting the locale there is IMHO not an API break. There's also precedent: In commit 0218d77 we recently changed the precision of that function.

IMHO fixing it centrally is better than wrapping all invocations of this with toLocaleString(). This also provides better consistency when mixing newer cockpit-* extension packages with an older cockpit-system (as happens in RHEL).