Improve integration test for interactive verification (#3495)
* Tweaks to the integ test to conform to the spec
Rust is a bit more insistent than legacy crypto...
* Improve documentation on request*Verification
* Check more things in the integration test
* Create an E2EKeyResponder
* Test verification with custom method list
* Add a test for SAS cancellation
* Update spec/integ/crypto/verification.spec.ts