FIX Ensure schema data includes attributes

[GuySartorelli]

Includes attributes in getSchemaDataDefaults() (excluding any duplicates and the value attribute, which would have caused problems).

To test

Assuming you have silverstripe/frameworktest installed:

1. Add this code to the Company class

   public function scaffoldSearchFields($_params = null)
   {
       $fields = parent::scaffoldSearchFields($_params);
       foreach ($fields as $field) {
           if ($field->getName() === 'Name') {
               $field->setAttribute('placeholder', 'this is my placeholder');
           }
       }
       return $fields;
   }

2. Go to the "Test ModelAdmin" section (/admin/test)

3. Click the magnifying glass in the top right, then expand "search options" - the "Name" field should have some placeholder text.

Also check that you can set up and use the formfields which were specifically changed.

Issue

• Form field attributes aren’t included in form schema #9124

[emteknetnz]

Tested locally, works well