Improved ref switcher dropdown performance

What does this MR do?

Removes jQuery creating elements, instead uses vanilla JS to create elements. This increase the performance significantly, previously with ~500 branches render time was approx. 30ms, with this change it dropped down to approx. 5ms.

The JSON now returns a maximum of 100 branches & 100 tags. The user can then search for more if they require.

What are the relevant issue numbers?

Closes #18202 (closed)

app/assets/javascripts/project.js

@@ -94,8 +94,8 @@
                 link.className = 'is-active';
               }
-              link.textContent = ref.name;
-              link.dataset.ref = ref.name;
+              link.textContent = ref;
+              link.dataset.ref = ref;
               li.appendChild(link);
             }