feat: Move the SLA filter dropdown to UI folder (#9502)

# Pull Request Template

## Description

I moved the newly created SLA filter dropdown to the UI folder to use in
adding the Linear issue modal.

app/javascript/dashboard/components/ui/Dropdown/DropdownListItemButton.vue

@@ -0,0 +1,36 @@
+<script setup>
+defineProps({
+  buttonText: {
+    type: String,
+    default: '',
+  },
+  isActive: {
+    type: Boolean,
+    default: false,
+  },
+});
+</script>
+<template>
+  <button
+    class="relative inline-flex items-center justify-start w-full p-3 border-0 rounded-none first:rounded-t-xl last:rounded-b-xl h-11 hover:bg-slate-50 dark:hover:bg-slate-700 active:bg-slate-75 dark:active:bg-slate-800"
+    @click.stop="$emit('click')"
+    @mouseenter="$emit('mouseenter')"
+    @mouseleave="$emit('mouseleave')"
+    @focus="$emit('focus')"
+  >
+    <div class="inline-flex items-center gap-3 overflow-hidden">
+      <span
+        class="text-sm font-medium truncate text-slate-900 dark:text-slate-50"
+      >
+        {{ buttonText }}
+      </span>
+      <fluent-icon
+        v-if="isActive"
+        icon="checkmark"
+        size="18"
+        class="flex-shrink-0 text-slate-900 dark:text-slate-50"
+      />
+    </div>
+    <slot name="dropdown" />
+  </button>
+</template>