Allow specific block fields to be set as required

Problem/Motivation

Description

Currently, when creating or configuring blocks through the daisy_cms_layout_builder module, all block fields are optional by default.
It would be helpful to have a feature that allows developers or site builders to mark specific block fields as required, while leaving others optional.

This would enhance form validation, ensure data consistency, and provide better control over the block creation process.

Example use case

• A custom block has multiple fields such as:
• Title → should be required
• Subtitle → optional
• Image → required
• Description → optional