ensure `include-meta-resources` is supported consistently across `kpt fn` commands

[droot]

[droot]

Mostly likely, no work is required. I would like @phanimarupaka to audit the fn commands to see if everything is in place and consistent.

[phanimarupaka]

@droot kpt fn render should also support include-meta-resources flag consistent with kpt fn eval. With this flag, eval is more powerful and the functionality provided imperatively should also be provided declaratively.

Use case:
Consider an example where you want to set namespace and and also have the namespace value as substring of another field.

# mypkg/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: foo-deployment # kpt-set: ${ns}-deployment
  namespace: foo

# mypkg/Kptfile
apiVersion: kpt.dev/v1alpha2
kind: Kptfile
metadata:
  name: example
pipeline:
  mutators:
    - image: gcr.io/kpt-fn/apply-setters:v0.1
      configPath: setters-config.yaml
    - image: gcr.io/kpt-fn/set-namespace:v0.1
      configPath: namespace-config.yaml

# mypkg/setters-config.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: setters-config
data:
  ns: myspace

# mypkg/namespace-config.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: ns-config
data:
  namespace: foo # kpt-set: ${ns}

So using eval users can just update setter value to myspace ONCE and it can update the other function configs as well

kpt fn eval -i gcr.io/kpt-fn/apply-setters:v0.1 --fn-config setters-config.yaml --include-meta-resources
kpt fn eval -i gcr.io/kpt-fn/set-namespace:v0.1 --fn-config namespace-config.yaml

# mypkg/namespace-config.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: ns-config
data:
  namespace: myspace # kpt-set: ${ns}

# mypkg/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myspace-deployment # kpt-set: ${ns}-deployment
  namespace: myspace

This functionality is not offered by kpt fn render currently. Users must update both setters-config.yaml and namespace-config.yaml with value myspace and render the package to get the equivalent functionality of eval.

So we should support, --include-meta-resources feature for kpt fn render. But not sure if it should be offered as a flag for entire render command. We want it specified per function. So add a field to Function definition in Kptfile?