Creation date of process as a process and task list column

[henning-gerhardt]

Is your feature request related to a problem? Please describe.
While the duration of a process (create date until current day) is already available as a column in the process and task list the creation date of a process itself is missing (was available in 2.x).

Describe the solution you'd like
As the creation date of a process exists in the database and is used for the duration column displaying this value as a dd.mm.year (or yyyy/dd/mm depending on the used language (default date format of the selected language should be used)) on a date base (creation hour, minute and second are not needed) adding this date even as a selectable column list entry should be possible. In the task list the wording of the column should show that this date is the date of process creation and not some task date.