Image: Update to v1.7.0.

[Gacko]

Tests on workload clusters (not always required)

For changes in the chart, chart templates, and ingress controller container images, I executed the following tests
to verify them working in live enviromnents:

Test / Provider	AWS	Azure	KVM
Upgrade from previous version	✓
Existing Ingress resources are reconciled correctly	✓
Fresh install	✓
Fresh Ingress resources are reconciled correctly	✓

Testing was done using hello-world-app.

Hint for KVM:

kubectl port-forward -n kube-system svc/nginx-ingress-controller-app 8080:80
ingress_domain=host.configured.in.ingress; curl --connect-to "$ingress_domain:80:127.0.0.1:8080" "http://$ingress_domain" -v

[Gacko]

This PR also includes some minor changes regarding indention and template rendering, nothing functional.

[Gacko]

btw: I'll implement vendir once we aligned all the stuff from upstream, even the breaking ones, and released a new major version.

[Gacko]

Wasn't able to test it on Azure due to cluster creation issues.