Include the time zone in CP timestamps

[brandonkelly]

Description

Appends a time zone abbreviation to most formatted dates throughout the control panel, e.g. within element metadata tables and element indexes.

Under the hood, new showTimeZone arguments have been added to Formatter::asTime() and Formatter::asDateTime(), as well as the |datetime and |time Twig filters. When true is passed, the inferred time zone’s abbreviation will be appended to the result, like above.

Related issues

• Add timezone as user preference per site instead being a General setting #8518