Fix remaining typescript issues, enable tsc (#32840)

Fixes 79 typescript errors. Discovered at least two bugs in
`notifications.ts`, and I'm pretty sure this feature was at least
partially broken and may still be, I don't really know how to test it.

After this, only like ~10 typescript errors remain in the codebase but
those are harder to solve.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

web_src/js/features/comp/WebHookEditor.ts

@@ -23,7 +23,7 @@ export function initCompWebHookEditor() {
   }
 
   // some webhooks (like Gitea) allow to set the request method (GET/POST), and it would toggle the "Content Type" field
-  const httpMethodInput = document.querySelector('#http_method');
+  const httpMethodInput = document.querySelector<HTMLInputElement>('#http_method');
   if (httpMethodInput) {
     const updateContentType = function () {
       const visible = httpMethodInput.value === 'POST';