Context and objective

This PR aims to add the appropriate ARIA attributes (aria-invalid andaria-describedby) to form fields when validation errors are present.
The proposal is based on the recommendations ofWCAG 2.1 and specifically the techniqueARIA21, which describes the combined use ofaria-invalid="true" andaria-describedby="<TEXT_ERROR_ID>" AFTER user input validation. It seems particularly relevant to implement this since SymfonyUX's LiveComponent allows for an auto-validation system, enabling real-time error feedback to users as they fill out the form.
Concretely, users of screen readers will be informed of the presence of errors as soon as they focus on the form field, and if an explicit error message is associated, they can access it immediately.
Note that thearia-describedby attribute can point to one or more HTML elements, allowing multiple messages (for example, a help message and an error message) to be vocalized. This PR takes this possibility into account by associating each field with the text passages_field_id_help_ and_field_id_errors_ when applicable.

Twig Side

The proposal is integrated into all form themes through the main templateform_div_layout.html.twig, except for the filesbootstrap_4_layout.html.twig andbootstrap_4_horizontal_layout.html.twig. In these files, errors were initially placed inside the associated label, so it is not necessary to add thearia-describedby attribute. Errors will be vocalized automatically and immediately after the label content. Thearia-invalid="true" attribute remains necessary to indicate the presence of errors.

Let me know if this approach works for you, or if you would like me to modify any aspects.