Ability to set auth_jwt_leeway in policy resource

[anderius]

Currently, we must use snippets to configure auth_jwt_leeway (see https://nginx.org/en/docs/http/ngx_http_auth_jwt_module.html#auth_jwt_leeway).

It would be very nice if that was configurable directly in the policy resource (see https://docs.nginx.com/nginx-ingress-controller/configuration/policy-resource/#jwt-using-jwks-from-remote-location).

[github-actions]

Hi @anderius thanks for reporting!

Be sure to check out the docs and the Contributing Guidelines while you wait for a human to take a look at this 🙂

Cheers!