Add tooltip showing the time in UTC and hinting at the timezone of the timestamp in the page

[darkk]

The screenshot is done in UTC+3.
One page of wui shows measurement time in local time and another in UTC.
Looks like a bug :)

[hellais]

Oh yeah you are right, this is for sure a bug. The desired behaviour is that measurements from the wui should always be shown in the local time of the user as is shown in the first of the two pages.

Thanks for finding this!

[hellais]

@irl suggested on IRC that we add a tooltip specifying in which timezone a certain time is indicated in to make it clearer.

[irl]

Adding a tooltip to times/dates that gives an ISO8601 representation of the time/date including timezone to avoid any confusion.

[hellais]

The timezone does not mismatch anymore, however the tooltip is not currently implemented.

I am going to leave this open and rename it to add support for the tooltip.