add `widgets:sso:manage` scope (#1337)

## Description

Adds the `widgets:sso:manage` scope. Also makes `userId` optional (We
anticipate customer's using this widget without a corresponding AuthKit
user).

## Documentation

Does this require changes to the WorkOS Docs? E.g. the [API
Reference](https://workos.com/docs/reference) or code snippets need
updates.

```
[X] Yes
```

If yes, link a related docs PR and add a docs maintainer as a reviewer.
Their approval is required.