finish custom class and improved options overhaul

src/lib/RadioGroup.svelte

@@ -1,39 +1,13 @@
-<script lang="ts" module>
-	export type RadioGroupOption =
-		| {
-				value: string;
-				label?: string;
-		  }
-		| string;
-
-	/** getLabel returns the option label if it exists*/
-	const getLabel = (option: RadioGroupOption): string => {
-		if (typeof option === 'string') {
-			return option;
-		} else {
-			return option.label ?? option.value;
-		}
-	};
-
-	/** getValue returns the option value */
-	const getValue = (option: RadioGroupOption): string => {
-		if (typeof option === 'string') {
-			return option;
-		} else {
-			return option.value;
-		}
-	};
-</script>
-
 <script lang="ts">
 	import { RadioGroup, type RadioGroupProps } from 'melt/builders';
 	import type { ClassValue } from 'svelte/elements';
 	import { scale } from 'svelte/transition';
 	import Label from './Label.svelte';
 	import { validate } from '@svelte-toolkit/validate';
+	import { getLabel, getValue, type Option } from './util.js';
 
 	interface Props extends RadioGroupProps {
-		options: RadioGroupOption[];
+		options: Option[];
 		label?: string;
 		required?: boolean;
 		invalidMessage?: string;