Export FGA types (#1106)

## Description

- Exports types related to FGA module

## Documentation

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

```
[ ] Yes
```

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

src/index.ts

@@ -19,6 +19,7 @@ export * from './common/utils/pagination';
 export * from './directory-sync/interfaces';
 export * from './directory-sync/utils/get-primary-email';
 export * from './events/interfaces';
+export * from './fga/interfaces';
 export * from './organizations/interfaces';
 export * from './passwordless/interfaces';
 export * from './portal/interfaces';