oidc-signin-tool types are inconsistent with other auth types

[MichaelBelousov]

Perhaps there are more, but the scope field on TestBrowserAuthorizationClientConfiguration is called scopes elsewhere. This makes it annoying to write code that may inject a test auth client during tests.

https://github.com/iTwin/auth-clients/tree/main/packages/oidc-signin-tool

Or perhaps I misunderstand something, because the redirectUri is also not-plural (or an array type) in this type