v1.0.4: Create individual instance of editor for column

Currently if there are more than one editor in a page then the content from the last editor is overrides content of all other editor on submit.
This happens because editor is overridden.

$form->json('first_json_mapping_field', 'First');
$form->json('second_json_mapping_field','Second');
--->Submit the form and both the fields will have save data saved