Consider whether to add a ChainedTokenCredential

[RickWinter]

No description provided.

[JakeDern]

Some $.02 from us on the ArcData team who just looked into this today (loving the SDK so far btw) - We build libraries used across apps running in many environments e.g. locally with Azure CLI for dev, on K8s using Workload Identity, on VMs using IMDS, and on Arc enabled machines using HIMDS.

We also have unusual environments such as Arc Enabled VMs that have both HIMDS and IMDS available or even more exotic situations where we have to proxy token requests to some other endpoint. Often times we implement our own custom TokenCredential types in other languages along with custom chains to accommodate developing in these environments ergonomically.

We would very much be interested in a ChainedTokenCredential or expansion of the configurable sources under DefaultAzureCredential so that we can plug in more credential types including our own.