Add Wrapper and Column Class Options

I'm not sure why these options are necessary in the first place? They are determining layout, not anything to do with the widget itself. The layout in my opinion should be left to the form in which the field exists.

That said, if there is a valid reason to have the widget use these classes on the wrapping elements, then I support the patch at minimum.

This patch seems to be a good path to fix some other issues with the layout that are introduced by the widget.

@Orestis Nerantzis

I agree with @b_sharpe it a widget so do not need to add something for the layout but I tested it and found it could be useful sometimes, fixing a bit of layout issue of the field as well.

However there are few inputs :

1. Remove trailing spaces after $summary = []; and $elements = [];

modules/bootstrap_datetime_picker/src/Plugin/Field/FieldWidget/BootstrapDateTimeWidget.php

2. Need not to translate integers.

'#options' => [
        'col-sm-1' => $this->t('1'),
        'col-sm-2' => $this->t('2'),
        'col-sm-3' => $this->t('3'),
        'col-sm-4' => $this->t('4'),
        'col-sm-5' => $this->t('5'),
        'col-sm-6' => $this->t('6'),
        'col-sm-7' => $this->t('7'),
        'col-sm-8' => $this->t('8'),
        'col-sm-9' => $this->t('9'),
        'col-sm-10' => $this->t('10'),
        'col-sm-11' => $this->t('11'),
        'col-sm-12' => $this->t('12'),
      ],

3. Do not need extra single quotes in "<div class='" . $element['#wrapper_class'] . "'> and <div class='" . $element['#column_size_class'] . "'>";

Please fix, test these and resubmit the patch.

Thanks, nice work!

I have made the changes requested in #5. please review

Thanks to all of you. Pushed and released with tag 8.x-1.5. Please check at your end and feel free to re-open this ticket if any issue found.