Bugzilla

TimingsPanel and RequestListColumnWaterfall both built their ids from a
timing phase name, so the phases are mapped to literal ids.

RequestListColumnWaterfall reads the strings through a lazy Localization
rather than withLocalization: its tooltip is built in a mouseover handler
rather than during render, and it is rendered once per request, so there is
no reason to subscribe every row to the localization context.

The waterfall tooltips now pass the time as a number rather than a
preformatted string, so Fluent applies the locale's number formatting to it
where %S did not.

WIP