* Cypress: skip tests known to fail when using Rust crypto
... which means we can then run the cypress test suite against Element Web R to
check we aren't introducing regressions.
* Update cypress/e2e/register/register.spec.ts
* Use env var to detect rust crypto
* Hoist `skipIfRustCrypto` call earlier
* Add intercept of `config.json`
To help make sure that we run our tests against a known config, rather than
accidentally making requests to `matrix.org`.
* Remove now-redundant stubs of matrix.org files
Now that we intercept config.json, all this stuff is redundant.
* Reinstate fixture which is actually used
Turns out this is used after all
* Add a `map_style_url`
* disable failing axe check