Make a form validation handler | handle form messages

A Javascript handler for form|fields messages.

As a developer, I have been several times, in the awkward position, needing to implement custom code, that will co-operate with bs-form fields. So, many times I had the same thought. "What if bootstrap provided the base 'JS adapter' for its fields"

This PR tries to provide a Bootstrap component, that automatically handle browser validation messages, and in addition will give the opportunity to use custom, given feedback messages.

In advance, it contains JavaScript code, providing

• on form component:
  • method to clear these messages,
  • get FormData` (for ajax usage)
  • execute validation
  • access each formField instance
  • JS hook, through component configuration, where developers can use for Ajax submission (not provided by default) and/or attach any custom validation messages
• per field methods:
  • clear appended feedbacks
  • append success | error | info feedback messages

Needs:

• Documentation
• Tests
• Feedback

Cons: Adds a significant size as it introduces two new classes 🤔

Related #28414 close #28995

Preview : https://deploy-preview-34043--twbs-bootstrap.netlify.app/docs/5.2/forms/validation/#custom-styles