improved duration and minute selector (#2264)

* do not close modal if form is dirty
* deprecated TimesheetConfiguration
* inject timezone in form types
* cleanup usage of UserDateTimeFactory
* allow to configure increment steps for minutes
* use 15 minutes step for datetimepicker in project edit form
* use rounding rules for increments in minute select for begin and end
* allow duration in multi user and admin timesheet forms
* make dropdown values configurable

src/Controller/ExportController.php

@@ -143,6 +143,7 @@ class ExportController extends AbstractController
             'action' => $this->generateUrl('export', []),
             'include_user' => $this->isGranted('view_other_timesheet'),
             'method' => $method,
+            'timezone' => $this->getDateTimeFactory()->getTimezone()->getName(),
             'attr' => [
                 'id' => 'export-form'
             ]