feat: Add subtest for FunctionList behavior

[LucasRoesler]

Add tests to verify the ListFunctions behavior after we deploy some functions. This test also verifies listing functions in mutliple namespaces.

• Upgrade faas-cli proxy to 0.13.9 and handle breaking changes to the client initialization
• Refactor ProviderInfo test to use the new sdk types

Testing

kind create cluster

arkade install openfaas --basic-auth=false --clusterrole

kubectl create namespace certifier-test
kubectl annotate namespace/certifier-test openfaas="1"

export CERTIFIER_NAMESPACES=certifier-test

kubectl port-forward -n openfaas svc/gateway 8080:8080 &
make test-kubernetes