Description

Once the new ExternalToInternalTokenExchangeProvider and the new feature TOKEN_EXCHANGE_EXTERNAL_INTERNAL_V2 introduced in #40134 are available, it would be useful to have dedicated tests for version 2 of external to internal token exchange in a separate class, similar to what was done for Standard Token Exchange in #37105 so that they are independent from version 1.

For version 1 of token exchange, some tests for external to internal token exchange are located in KcOidcBrokerTokenExchangeTest, which is part of org/keycloak/testsuite/broker. It should be evaluated whether it’s better to move the new tests to org/keycloak/testsuite/oauth/tokenexchange.