Investigate cross-tenant managed identity federation

[PalmEmanuel]

Might already be supported but could in that case use some clarification.

[svrooij]

Feel free to use this code as a guide to implement this in your module.

want to enable others to get rid of secrets, that is my only goal.

[PalmEmanuel]

Haven't added anything more to this, but I confirmed a while back that it works fine if you combine two token flows by getting a Managed Identity token first and then using it as the Workload Identity client assertion input.

Will keep it open for future improvements to potentially combine the flow.