feat: exposing loadBalancer.externalTrafficPolicy value

[clems71]

Hello Caddy team!

It is often desirable to preserve the client IP when using an ingress controller. However, to achieve this, the LoadBalancer externalTrafficPolicy need to be set to Local (see references at end of PR).

This PR proposes this: exposing the externalTrafficPolicy in the values.

References

• https://kubernetes.io/docs/tasks/access-application-cluster/create-external-load-balancer/#preserving-the-client-source-ip
• https://learn.microsoft.com/en-us/azure/aks/load-balancer-standard#maintain-the-clients-ip-on-inbound-connections

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (aaf3e54) 42.19% compared to head (5a7fe2a) 42.19%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #168 +/- ## ======================================= Coverage 42.19% 42.19% ======================================= Files 12 12 Lines 365 365 ======================================= Hits 154 154 Misses 210 210 Partials 1 1 ```

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[clems71]

Hello @mavimo ! Anything else I need to do on my end on this PR?

[mavimo]

@clems71 no and thank you for your contribution!