Form Validation customization

[Splash-Nemo]

Prerequisites

• [X] I have searched for duplicate or closed feature requests
• [X] I have read the contributing guidelines

Proposal

Implement robust client-side validation in Bootstrap forms with customizable error messages and styling options.

From https://github.com/twbs/bootstrap/issues/40573#issuecomment-2183607649:

I'm suggesting we make Bootstrap forms better by adding strong validation features. This means error messages that can be customized for different needs, like required fields or wrong email formats. Also, we'd add options for changing how forms look, so developers can match them to different designs or brand styles. They could adjust colors, fonts, and animations easily. This would give more freedom and make websites easier to use. Thanks for considering this improvement.

Motivation and context

It will ensure accurate data entry and also enhance user experience with customizable error messages and styling options, optimizing usability and reliability.