[widget_datetimepicker] allow to set data-timeheightintimepicker
[widget_datetimepicker] allow to set data-timeheightintimepicker

This allows to change the cell height via css and
still have the correct positioning on opening

knowthelist/fhem-tablet-ui,knowthelist/fhem-tablet-ui,knowthelist/fhem-tablet-ui,knowthelist/fhem-tablet-ui,knowthelist/fhem-tablet-ui