title	issue
Improvement validate with white space	NEXT-17481

Core

Changed StringFieldSerializer::encode in src/Core/Framework/DataAbstractionLayer/FieldSerializer/StringFieldSerializer.php.

Storefront

Added function _onValidateRequired in storefront/src/plugin/forms/form-validation.plugin.js to validate required field.
Added data attributes data-form-validation-required and data-form-validation-required-message to validate and show the error message for the required field in the following files:
- storefront/component/address/address-form.html.twig
- storefront/component/address/address-personal.html.twig
- storefront/component/address/address-personal-company.html.twig