Provided validation and helper slot for FwbSelect #242 (#254)

* feat(fwb-select): Add validation and helper slot

* docs(docs-select): Add validation and helper slot examples

docs/components/select/examples/FwbSelectExampleValidation.vue

@@ -0,0 +1,33 @@
+<template>
+  <div class="vp-raw">
+    <fwb-select
+      v-model="selected"
+      :options="countries"
+      label="Select a country"
+      validation-status="success"
+    />
+    <hr class="mt-4 border-0">
+    <fwb-select
+      v-model="selected"
+      :options="countries"
+      label="Select a country"
+      validation-status="error"
+    >
+      <template #validationMessage>
+        Please select a country
+      </template>
+    </fwb-select>
+  </div>
+</template>
+
+<script lang="ts" setup>
+import { ref } from 'vue'
+import { FwbSelect } from '../../../../src/index'
+
+const selected = ref('')
+const countries = [
+  { value: 'us', name: 'United States' },
+  { value: 'ca', name: 'Canada' },
+  { value: 'fr', name: 'France' },
+]
+</script>