test: semantically splits admin e2e (#10213)

Improves the admin e2e test splitting by grouping them by type with
semantic names as opposed to numerically. This will provide much needed
clarity to exactly _where_ new admin tests should be written and help to
quickly distinguish the areas of failure within the CI overview.

test/plugin-form-builder/e2e.spec.ts

@@ -15,7 +15,7 @@ import { POLL_TOPASS_TIMEOUT, TEST_TIMEOUT_LONG } from '../playwright.config.js'
 const filename = fileURLToPath(import.meta.url)
 const dirname = path.dirname(filename)
 
-test.describe('Form Builder', () => {
+test.describe('Form Builder Plugin', () => {
   let page: Page
   let formsUrl: AdminUrlUtil
   let submissionsUrl: AdminUrlUtil