Description

Follow-up of #47339 and #47478 .

This task is about removal of identity-brokering-api V1 and make identity-brokering-api V2 enabled by default.

In relation to that, we can also:

• Entirely remove built-in client broker as it will not be needed for anything (related task for not creating it with identity-brokering-api V2 was Skip creation of broker client when identity-broker-api:v1 is disabled #46587 )
• Remove the IDP switch "Store tokens readable" (may also need DB schema update to remove switch addReadTokenRoleOnCreate from IdentityProviderModel and related field ADD_TOKEN_ROLE from IdentityPRoviderEntity in DB). Hopefully it can be removed from IdentityProviderRepresentation as well, but not 100% sure (due the possible issues with import realm from old JSON file).