feat(vector): add secret annotations

[al-cheb]

This allow to inject external secrets, like e.g. Hashicorp Vault.

username: "${vault:secret/data/path#property#version}"
 password: "${vault:secret/data/vector#password#1}"

E.g.:

$ helm template -n vector . --set secrets.generic.abc=test

# Source: vector/templates/secret.yaml
apiVersion: v1
kind: Secret
metadata:
  name: release-name-vector
  namespace: "vector"
  labels:
    helm.sh/chart: vector-0.43.1
    app.kubernetes.io/name: vector
    app.kubernetes.io/instance: release-name
    app.kubernetes.io/component: Aggregator
    app.kubernetes.io/version: "0.47.0-distroless-libc"
    app.kubernetes.io/managed-by: Helm
    
  annotations:
    abc: something
type: Opaque
data:
  abc: "dGVzdA=="