Makes configuration form store settings using the correct structure of...
This merge request introduces the following changes:
- Changes the BundleSettingsForm to store the config values in valid structure with the config schema.
- Introduces a langcode value in the configuration object ( required since there is a translatable element in the schema ). The form sets it to a default value 'en' if not present.
- Changes the 'local_task_label' schema type to 'label', to make use of the already existing type and validation.
- Adds a hook_update to change existing configurations.
Closes #3514273