Clean up policy name filter

- abstract out constants
- clean up test
- convert class to gl-

ee/app/assets/javascripts/threat_monitoring/components/alerts/alert_filters.vue

 <script>
 import { GlFormCheckbox, GlFormGroup, GlSearchBoxByType } from '@gitlab/ui';
 import { s__ } from '~/locale';
-import { DEFAULT_FILTERS } from './constants';
+import { DEBOUNCE, DEFAULT_FILTERS } from './constants';
 
 export default {
+  DEBOUNCE,
   DEFAULT_DISMISSED_FILTER: true,
   components: { GlFormCheckbox, GlFormGroup, GlSearchBoxByType },
   props: {
@@ -46,7 +47,7 @@ export default {
     <div>
       <h5 class="gl-mt-0">{{ $options.i18n.POLICY_NAME_FILTER_TITLE }}</h5>
       <gl-search-box-by-type
-        debounce="250"
+        :debounce="$options.DEBOUNCE"
         :placeholder="$options.i18n.POLICY_NAME_FILTER_PLACEHOLDER"
         @input="handleSearch"
       />

ee/app/assets/javascripts/threat_monitoring/components/alerts/constants.js

@@ -56,3 +56,5 @@ export const PAGE_SIZE = 20;
 export const DEFAULT_FILTERS = { statuses: ['TRIGGERED', 'ACKNOWLEDGED'] };
 
 export const DOMAIN = 'threat_monitoring';
+
+export const DEBOUNCE = 250;

ee/app/assets/javascripts/threat_monitoring/components/network_policy_list.vue

@@ -187,7 +187,7 @@ export default {
     >
       <gl-sprintf :message="$options.autodevopsNoticeDescription">
         <template #monospaced="{ content }">
-          <span class="monospace">{{ content }}</span>
+          <span class="gl-font-monospace">{{ content }}</span>
         </template>
         <template #link="{ content }">
           <gl-link :href="documentationFullPath">{{ content }}</gl-link>

ee/spec/frontend/threat_monitoring/components/alerts/alert_filters_spec.js

@@ -31,12 +31,12 @@ describe('AlertFilters component', () => {
       });
 
       it('does emit an event with a user-defined string', async () => {
-        const term = 'abc';
+        const searchTerm = 'abc';
         const search = findGlSearch();
-        search.vm.$emit('input', term);
+        search.vm.$emit('input', searchTerm);
         await wrapper.vm.$nextTick();
         expect(wrapper.emitted('filter-change')).toStrictEqual([
-          [{ ...DEFAULT_FILTERS, searchTerm: 'abc' }],
+          [{ ...DEFAULT_FILTERS, searchTerm }],
         ]);
       });
     });