Feature: search suggestions for search and quick launch (#2775)

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Co-authored-by: shamoon <4887959+shamoon@users.noreply.github.com>

src/pages/api/search/searchSuggestion.js

@@ -0,0 +1,23 @@
+import { searchProviders } from "components/widgets/search/search";
+import cachedFetch from "utils/proxy/cached-fetch";
+import { widgetsFromConfig } from "utils/config/widget-helpers";
+
+export default async function handler(req, res) {
+  const { query, providerName } = req.query;
+
+  const provider = Object.values(searchProviders).find(({ name }) => name === providerName);
+
+  if (provider.name === "Custom") {
+    const widgets = await widgetsFromConfig();
+    const searchWidget = widgets.find((w) => w.type === "search");
+
+    provider.url = searchWidget.options.url;
+    provider.suggestionUrl = searchWidget.options.suggestionUrl;
+  }
+
+  if (!provider.suggestionUrl) {
+    return res.json([query, []]); // Responde with the same array format but with no suggestions.
+  }
+
+  return res.send(await cachedFetch(`${provider.suggestionUrl}${encodeURIComponent(query)}`, 5));
+}