Move threads e2e tests over to cypress (#8501)

* Add non-consent (default) Synapse template

* Add consent test

* Add create room test

* Stash work

* Initial threads tests

* fix

* Delete old threads e2e tests, plan new ones

* Fix typed s'more

* Try something else

* specify d.ts

* Fix types once and for all?

* Fix the consent tests

* Iterate threads test harness

* Fix dispatcher types

* Iterate threads test

* fix typing

* Alternative import attempt

* let it break let it break let it break

* Tweak types

* Stash

* delint and update docs

* null-guard scrollIntoView

* Iterate threads test

* Apply suggestions from code review

package.json

@@ -166,7 +166,7 @@
     "babel-jest": "^26.6.3",
     "blob-polyfill": "^6.0.20211015",
     "chokidar": "^3.5.1",
-    "cypress": "^9.5.4",
+    "cypress": "^9.6.1",
     "enzyme": "^3.11.0",
     "enzyme-to-json": "^3.6.2",
     "eslint": "8.9.0",