[FEATURE REQ] Azure.Identity/DAC should log ClientId for user-assigned managed identities

[christothes]

Library name

Azure.Identity

Please describe the feature.

Today we don't directly log the ClientId when selecting a user-assigned identity to use with ManagedIdentityCredential. Customers instead need to change verbosity and dig into MSAL logs instead which isn't nearly as obvious.

We expect multiple user-assigned managed identity scenarios to become much more common with future Aspire work, so surfacing the ClientId will make it a lot easier to spot config problems (i.e., am I trying to access Storage with an identity scoped to just reading photos? or the identity created for the logical container? or ...?).