CMS-54015 Forms

[marin-karamihalev]

• Forms feature detection: Added GraphQL introspection to detect forms support in Optimizely CMS
• Form content types: Defined TypeScript types for form containers, inputs, selections, textareas, submit, and reset buttons
• Form component registry: Implemented initForms() to register form components with the SDK
• Alloy template components: Created React components for form rendering (FormContainer, FormInput, FormSelection, FormTextarea, FormSubmit, FormReset)
• SDK integration: Extended SDK's server-side React utilities to support form component rendering (This is experimental, the only way I could think of currently to allow access to the form container properties)
• Documentation: Added forms guide and updated modeling documentation
• Support for client side validation, form steps and form rules