…lastic#89947  (elastic#89973)

## Summary

Adds e2e and unit tests for PR:
elastic#89947

* Adds e2e tests for create_index
* Adds e2e tests for get_privileges
* Adds unit test for use_privilege_user
* Adds exhaustive switch for the roles in the e2e tests
* Adds some typescript barrel rolls for the .json scripts to make TypeScript a bit more readable when doing imports 
* Fixes some of the types that were not matched up with the recent privilege endpoint

### Checklist

- [x] [Unit or functional tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html) were updated or added to match the most common scenarios

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