Refactor Field components with const arrow functions (#1261)

## Summary
- convert all remaining Field components to const arrow functions
- document the refactor in the CHANGELOG

## Testing
- `npm run lint`
- `npm run build`


------
https://chatgpt.com/codex/tasks/task_e_68684db1b6b88331837307a54e3f9dc1

src/components/FieldAutocomplete.tsx

@@ -1,4 +1,3 @@
-import React from 'react'
 import Block from './Block'
 import InputAutocomplete, { InputAutocompleteProps } from './InputAutocomplete'
 
@@ -8,10 +7,12 @@ type FieldAutocompleteProps = InputAutocompleteProps & {
 };
 
 
-export default class FieldAutocomplete extends React.Component<FieldAutocompleteProps> {
-  render() {
-    return <Block label={this.props.label}>
-      <InputAutocomplete {...this.props} />
+const FieldAutocomplete: React.FC<FieldAutocompleteProps> = (props) => {
+  return (
+    <Block label={props.label}>
+      <InputAutocomplete {...props} />
     </Block>
-  }
-}
+  );
+};
+
+export default FieldAutocomplete;