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/DropdownList.vue

@@ -0,0 +1,80 @@
+<script setup>
+import { ref, computed } from 'vue';
+import { picoSearch } from '@scmmishra/pico-search';
+import ListItemButton from './DropdownListItemButton.vue';
+import DropdownSearch from './DropdownSearch.vue';
+import DropdownEmptyState from './DropdownEmptyState.vue';
+
+const props = defineProps({
+  listItems: {
+    type: Array,
+    default: () => [],
+  },
+  enableSearch: {
+    type: Boolean,
+    default: false,
+  },
+  inputPlaceholder: {
+    type: String,
+    default: '',
+  },
+  activeFilterId: {
+    type: Number,
+    default: null,
+  },
+  showClearFilter: {
+    type: Boolean,
+    default: false,
+  },
+});
+
+const searchTerm = ref('');
+
+const onSearch = value => {
+  searchTerm.value = value;
+};
+
+const filteredListItems = computed(() => {
+  if (!searchTerm.value) return props.listItems;
+  return picoSearch(props.listItems, searchTerm.value, ['name']);
+});
+
+const isDropdownListEmpty = computed(() => {
+  return !filteredListItems.value.length;
+});
+
+const isFilterActive = id => {
+  if (!props.activeFilterId) return false;
+  return id === props.activeFilterId;
+};
+</script>
+<template>
+  <div
+    class="absolute z-20 w-40 bg-white border shadow dark:bg-slate-800 rounded-xl border-slate-50 dark:border-slate-700/50 max-h-[400px]"
+    @click.stop
+  >
+    <slot name="search">
+      <dropdown-search
+        v-if="enableSearch && listItems.length"
+        :input-value="searchTerm"
+        :input-placeholder="inputPlaceholder"
+        :show-clear-filter="showClearFilter"
+        @input="onSearch"
+        @click="$emit('removeFilter')"
+      />
+    </slot>
+    <slot name="listItem">
+      <dropdown-empty-state
+        v-if="isDropdownListEmpty"
+        :message="$t('REPORT.FILTER_ACTIONS.EMPTY_LIST')"
+      />
+      <list-item-button
+        v-for="item in filteredListItems"
+        :key="item.id"
+        :is-active="isFilterActive(item.id)"
+        :button-text="item.name"
+        @click="$emit('click', item)"
+      />
+    </slot>
+  </div>
+</template>