add NV policy chart and values configs

[hadams95]

Adds neuvector security policies and config to gen3-helm

[swaphb]

LGTM

[krumware]

I'd like to also surface the new values to the helm/gen3 values so that they're more prominent.

from slack, it might also be helpful to go ahead and add the global variable and prepare for adding a conditional chart dependency

neuvector:
  enabled: false
  policies:
    ## on the fence about this variable name
    include: true
    defaultMode: Monitor
  nameOverride: ""
  fullnameOverride: ""
  # hostname/service name for our DB
  DB_HOST: development-gen3-postgresql
  # Prefix for relevant services deployed through Argo
  ARGOCD_PREFIX: development-gen3
  # Neuvector policy enforcement mode
  # dev: Monitor
  # prod: Protect
  ingress:
    # service name of your ingress controller
    controller: nginx-ingress-controller
    # installation namespace of your ingress controller
    namespace: nginx
    # classname of your ingress
    class: nginx

[hadams95]

@krumware Pinging for re-review, should have knocked out your change requests

[krumware]

Made a few changes to resolve linting and to add some references as inline docs.
I'd like to add a little bit more inline documentation about the DB_HOST variable, a little unclear to new folks what that's for. But I think it's good to go for now 👍