Implement OpenID module (#599) (#1812)

* Implement OpenID module (#599)

- Unrelated: change Riot references to Element in client API routing

Signed-off-by: Bruce MacDonald <contact@bruce-macdonald.com>

* OpenID module tweaks (#599)

- specify expiry is ms rather than vague ts
- add OpenID token lifetime to configuration
- use Go naming conventions for the path params
- store plaintext token rather than hash
- remove openid table sqllite mutex

* Add default OpenID token lifetime (#599)

* Update dendrite-config.yaml

Co-authored-by: Kegsay <kegsay@gmail.com>
Co-authored-by: Kegsay <kegan@matrix.org>

userapi/userapi_test.go

@@ -26,7 +26,7 @@ const (
 func MustMakeInternalAPI(t *testing.T) (api.UserInternalAPI, accounts.Database) {
 	accountDB, err := accounts.NewDatabase(&config.DatabaseOptions{
 		ConnectionString: "file::memory:",
-	}, serverName, bcrypt.MinCost)
+	}, serverName, bcrypt.MinCost, config.DefaultOpenIDTokenLifetimeMS)
 	if err != nil {
 		t.Fatalf("failed to create account DB: %s", err)
 	}