[Pattern][Draft] Forms layout

[aweell]

Design of a layout-pattern-form to provide a better understanding of form layout composition.

Documentation schema

• Overview
• Usage
• Variants
• Dedicated page
• Dialog
• Anatomy
• Data inputs
• Buttons
• Form validation
• Helping users
• Progressive disclosure
• Layout
• Accessibility
• Related links

Accessibility resources:
https://www.w3.org/WAI/tutorials/forms/instructions/

Review WCAG 2.2 following SC:

• All inputs in a form are associated with a corresponding label element. SC 3.2.2
• Use fieldset and legend elements where appropriate. SC 1.3.1
• Inputs use autocomplete where appropriate. SC 1.3.5
• Make sure that form input errors are displayed in list above the form after submission. SC 3.3.1
• Associate input error messaging with the input it corresponds to. SC 3.3.1
• Make sure that error, warning, and success states are not visually communicated by just color. SC 1.4.1

[aweell]

Closed via #317