Use i18next translation features for measurements panel options

[huddlej]

Description

As @tsibley originally noted:

Labels like [label="Show measurement threshold(s)"] should go thru our i18n framework (i18next) so they can be translated in the future.

label={t("Show measurement threshold(s)")}

Once they do, we can avoid the ugly "(s)" by using the standard pluralization/number agreement features, e.g. something like:

label={t("Show measurement threshold", {count: collection.thresholds.length})}

with corresponding translations, e.g. for en something like:

{
  "Show measurement threshold_one": "Show measurement threshold",
  "Show measurement threshold_others": "Show measurement thresholds",
}