fix(ui): respect line breaks in builder text and heading elements

Author: psychedelicious

invokeai/frontend/web/src/features/nodes/components/sidePanel/builder/HeadingElementContent.tsx

@@ -8,6 +8,7 @@ import { useTranslation } from 'react-i18next';
 const headingSx: SystemStyleObject = {
   fontWeight: 'bold',
   fontSize: '2xl',
+  whiteSpace: 'pre-wrap',
   '&[data-is-empty="true"]': {
     opacity: 0.3,
   },

invokeai/frontend/web/src/features/nodes/components/sidePanel/builder/TextElementContent.tsx

@@ -7,6 +7,7 @@ import { useTranslation } from 'react-i18next';
 
 const textSx: SystemStyleObject = {
   fontSize: 'md',
+  whiteSpace: 'pre-wrap',
   overflowWrap: 'anywhere',
   '&[data-is-empty="true"]': {
     opacity: 0.3,