feat: add sort to GET /authors endpoint

[niclim]

Adds sortKey and sortOrder query parameters on the GET /authors endpoint.

Valid options for sortKey are "name", "created_at", "updated_at" and valid options are sortOrder are "asc", "desc"

Sample request: curl http://localhost:3030/authors?sortKey=name&sortOrder=desc

[github-actions]

APIs Changed

API	Operation Changes	Checks
openapi.yml (preview)	1 operation changed (view changelog)	⚠️ 2 / 110 failed

Summary of API changes for commit (075915b)