[PUI] Add "index" page for build orders (#8287)

* Add "index" page for build orders

- Make consistent with other pages
- Allow plugin panels here
- Prepare for future development

* Rearrange URLs for "manufacturing"

- Provide same format as other order types
- Allow for other sub-pages under "manufacturing" in the future

* Fix breadcrumbs

* Adjust playwright tests

src/frontend/tests/pui_tables.spec.ts

@@ -24,7 +24,7 @@ test('Tables - Filters', async ({ page }) => {
   await doQuickLogin(page);
 
   // Head to the "build order list" page
-  await page.goto(`${baseUrl}/build/`);
+  await page.goto(`${baseUrl}/manufacturing/index/`);
 
   await setFilter(page, 'Status', 'Complete');
   await setFilter(page, 'Responsible', 'allaccess');