Refactor htmx and fetch-action related code (#37186)

This is the first step (the hardest part):

* repo file list last commit message lazy load
* admin server status monitor
* watch/unwatch (normal page, watchers page)
* star/unstar (normal page, watchers page)
* project view, delete column
* workflow dispatch, switch the branch
* commit page: load branches and tags referencing this commit

The legacy "data-redirect" attribute is removed, it only makes the page
reload (sometimes using an incorrect link).

Also did cleanup for some devtest pages.

types.d.ts

@@ -41,6 +41,13 @@ declare module 'htmx.org/dist/htmx.esm.js' {
   export default value;
 }
 
+declare module 'idiomorph' {
+  interface Idiomorph {
+    morph(existing: Node | string, replacement: Node | string, options?: {morphStyle: 'innerHTML' | 'outerHTML'}): void;
+  }
+  export const Idiomorph: Idiomorph;
+}
+
 declare module 'swagger-ui-dist/swagger-ui-es-bundle.js' {
   const value = await import('swagger-ui-dist');
   export default value.SwaggerUIBundle;