Util for formatting dates with prewired locale and advanced settings

[Dosant]

Describe the feature:

Currently there is no centralized and recommended way for date formatting. Apps use different methods like:

• native window.Intl,
• moment.js,
• FormattedDate / FormattedTime from@kbn/i18n-react (re-exported from react-intl).

There're multiple things that have to be taken into account and have to be done ad-hoc now that leads to inconcistencies and larger developer effort:

• Browser locale
• Kibana's lang
• Advanced settings like dateFormat and dateFormat:tz``dataFormat:dow

Design considerations: (in my opionin)

• Set of the utils should support date and time formating, both absolute and relative. Timezone should default to dateFormat:tz from advanced settings
• The utils should be easy to use without much boileraplate. Requiring explicitly passing uiSettings into the util is not ok.
• Returning strings with native js is a priority . React wrapper is nice to have

Implementation ideas

• Think if they should be part of @kbn/i18n since we already have react utils in @kbn/i18n-react. Then consider if @kbn/i18n-reactcan use preferences from advanced settings by default.

Needed for

This ask came up multiple times in the past, but the latest ask was from the observability team @dgieselaar @spong

Related

https://github.com/elastic/kibana/issues/178115

[elasticmachine]

Pinging @elastic/appex-sharedux (Team:SharedUX)

[vadimkibana]

Discussed this with Kevin and added it to our prioritization board, currently this has 6mo horizon.