Convert frontend code to typescript (#31559)

None of the frontend js/ts files was touched besides these two commands
(edit: no longer true, I touched one file in
61105d0618
because of a deprecation that was not showing before the rename).

`tsc` currently reports 778 errors, so I have disabled it in CI as
planned.

Everything appears to work fine.

web_src/js/features/repo-common.ts

@@ -0,0 +1,83 @@
+import $ from 'jquery';
+import {hideElem, queryElems, showElem} from '../utils/dom.ts';
+import {POST} from '../modules/fetch.ts';
+import {showErrorToast} from '../modules/toast.ts';
+import {sleep} from '../utils.ts';
+
+async function onDownloadArchive(e) {
+  e.preventDefault();
+  // there are many places using the "archive-link", eg: the dropdown on the repo code page, the release list
+  const el = e.target.closest('a.archive-link[href]');
+  const targetLoading = el.closest('.ui.dropdown') ?? el;
+  targetLoading.classList.add('is-loading', 'loading-icon-2px');
+  try {
+    for (let tryCount = 0; ;tryCount++) {
+      const response = await POST(el.href);
+      if (!response.ok) throw new Error(`Invalid server response: ${response.status}`);
+
+      const data = await response.json();
+      if (data.complete) break;
+      await sleep(Math.min((tryCount + 1) * 750, 2000));
+    }
+    window.location.href = el.href; // the archive is ready, start real downloading
+  } catch (e) {
+    console.error(e);
+    showErrorToast(`Failed to download the archive: ${e}`, {duration: 2500});
+  } finally {
+    targetLoading.classList.remove('is-loading', 'loading-icon-2px');
+  }
+}
+
+export function initRepoArchiveLinks() {
+  queryElems('a.archive-link[href]', (el) => el.addEventListener('click', onDownloadArchive));
+}
+
+export function initRepoCloneLink() {
+  const $repoCloneSsh = $('#repo-clone-ssh');
+  const $repoCloneHttps = $('#repo-clone-https');
+  const $inputLink = $('#repo-clone-url');
+
+  if ((!$repoCloneSsh.length && !$repoCloneHttps.length) || !$inputLink.length) {
+    return;
+  }
+
+  $repoCloneSsh.on('click', () => {
+    localStorage.setItem('repo-clone-protocol', 'ssh');
+    window.updateCloneStates();
+  });
+  $repoCloneHttps.on('click', () => {
+    localStorage.setItem('repo-clone-protocol', 'https');
+    window.updateCloneStates();
+  });
+
+  $inputLink.on('focus', () => {
+    $inputLink.trigger('select');
+  });
+}
+
+export function initRepoCommonBranchOrTagDropdown(selector) {
+  $(selector).each(function () {
+    const $dropdown = $(this);
+    $dropdown.find('.reference.column').on('click', function () {
+      hideElem($dropdown.find('.scrolling.reference-list-menu'));
+      showElem($($(this).data('target')));
+      return false;
+    });
+  });
+}
+
+export function initRepoCommonFilterSearchDropdown(selector) {
+  const $dropdown = $(selector);
+  if (!$dropdown.length) return;
+
+  $dropdown.dropdown({
+    fullTextSearch: 'exact',
+    selectOnKeydown: false,
+    onChange(_text, _value, $choice) {
+      if ($choice[0].getAttribute('data-url')) {
+        window.location.href = $choice[0].getAttribute('data-url');
+      }
+    },
+    message: {noResults: $dropdown[0].getAttribute('data-no-results')},
+  });
+}