Use vitest for some EW unit tests (#33816)

* Use vitest for some EW unit tests

* Ensure library builds are done before unit tests

* Stabilise jest tests

* Move more tests over

* Make sonar happier

* Update types/node for happy-dom compat again

* Decrease max-workers to stabilise jest tests

* Split jest over 3 runners to alleviate memory woes

* Switch jest to runInBand

* Attempt to deflake jest tests

* tweak coverage

* tweak coverage

apps/web/package.json

@@ -30,6 +30,7 @@
         "lint:types": "nx lint:types",
         "lint:style": "stylelint \"res/css/**/*.pcss\"",
         "test": "nx test:unit",
+        "test:vitest": "nx test:vitest",
         "test:playwright": "nx test:playwright --",
         "test:playwright:open": "nx test:playwright -- --ui",
         "test:playwright:screenshots": "nx test:playwright:screenshots --",
@@ -129,6 +130,7 @@
         "@element-hq/element-call-embedded": "0.20.1",
         "@element-hq/element-web-playwright-common": "workspace:*",
         "@fetch-mock/jest": "^0.2.20",
+        "@fetch-mock/vitest": "^0.2.18",
         "@jest/globals": "^30.2.0",
         "@peculiar/webcrypto": "^1.4.3",
         "@playwright/test": "catalog:",
@@ -190,6 +192,7 @@
         "express": "^5.0.0",
         "fake-indexeddb": "^6.0.0",
         "file-loader": "^6.0.0",
+        "happy-dom": "^20.10.2",
         "html-webpack-plugin": "^5.5.3",
         "identity-obj-proxy": "^3.0.0",
         "jest": "^30.0.0",
@@ -226,6 +229,7 @@
         "testcontainers": "^12.0.0",
         "typescript": "catalog:",
         "util": "^0.12.5",
+        "vitest": "catalog:",
         "web-streams-polyfill": "^4.0.0",
         "webpack": "^5.89.0",
         "webpack-bundle-analyzer": "^5.0.0",