OIDC: Revoke access and refresh tokens on sign out

[kerryarchibald]

Instead of calling /logout on the homeserver we need to revoke access and refresh tokens using

TBD: who is responsible for killing sessions afa device list? call delete device during logout?

AC:

• access and refresh tokens are revoked on sign out

[kerryarchibald]

Closed by matrix-org/matrix-react-sdk#11718