Fix incompatibility with Views Enity Form Field

This also conflicts with the Bookmarks module. Would be nice to allow users to manually sort their favorites.

The logic behind this comes from Work with Views Bulk Operations (#2013839) → via
75bed85 by @istryker, and was carried over to Drupal 8 via ef33afc without near as much documentation about why.

Digging a bit more to find out if we can get this to play nicely instead of outright removing the core submit button (@istryker, it would be nice to get your input since you originally wrote this logic for D7).

Patch #10 is not a patch, but is instead a suggested code implementation. It might be best to have documented this in a comment with a <code> block.

Also, no need to list the screenshot at the top.

Patch #9 failed to apply on 2.1.3. Attempted a re-roll to no avail: got a type error:

TypeError: base64_decode(): Argument #1 ($string) must be of type string, array given in base64_decode() (line 515 of core/modules/views/src/Plugin/views/field/BulkForm.php).

Just a note about the condition logic in #9: rather than check if the module is enabled, It might be better to check whether any views fields are an instance of EntityFormField.

use Drupal\views_entity_form_field\Plugin\views\field\EntityFormField;
  ...
  // Check if any fields are entity form fields.
  $entity_form_fields = array_filter($view->field, function ($field) {
    return $field instanceof EntityFormField;
  });
  $using__views_entity_form_field = !empty($entity_form_fields);

This may be blocked: Views Entity Form Field → notes the following in its documentation:

There is an issue with Views that use Bulk Form Operations - BFO takes over the submit button and will throw validation errors if there are no BFO checkboxes checked. It's suggested to not use both modules on the same View for now.

Re-roll of #9 🐛 Fix incompatibility with Views Enity Form Field Needs work for 2.1.x-dev.

However, this re-roll is experiencing the error noted in #14 🐛 Fix incompatibility with Views Enity Form Field Needs work .

Makes change noted in #15 🐛 Fix incompatibility with Views Enity Form Field Needs work .

Still experiencing the error noted in #14 🐛 Fix incompatibility with Views Enity Form Field Needs work .

Patch #19 🐛 Fix incompatibility with Views Enity Form Field Needs work applied clean on 2.1.3, but changes don't save. I get an "No Action option selected" page error instead.

#20 🐛 Fix incompatibility with Views Enity Form Field Needs work failed to apply.

I bumped into this issue today and have put together a patch that might work better.

This is a partial refactor of how the module operates, I've (re)moved the hook_form_alter() and hook_form_submit() code into DraggableViewsField, utilizing the parent BulkForm methods of viewsFormSubmit (and viewsFormValidate) instead of doing that whole replace submit button business. My limited testing seems to indicate that it solves the interoperability problem with views entity form field without having to do any special casing for that module.

I won't put this to Needs Review or a MR as the tests have not been updated and it feels like I've just done a partial refactor that, while it does fix this particular issue, if committed would leave the module in a bit of a mixed up state.

The patch should apply against the production 2.1.3 release.

I might complete the refactor in another ticket, time permitting.