Consider making `IdentityResult.Failed(List<IdentityError>? errors)` public

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Is your feature request related to a problem? Please describe the problem.

I wasn't sure if this should be labeled as API Change or Design Proposal. `ItentityResult.Failed(params IdentityError[] errors)` is public, but if you have built a `List`, then using that method means converting your list to array. There is `IdentityResult.Failed(List? errors)`, but for some reason it's marked internal, and looking at the source code, I don't see a reason it couldn't be public.

### Describe the solution you'd like

Change `IdentityResult.Failed(List? errors)` from `internal` to `public`.

### Additional context

_No response_