Support basic auth in streams mode

[maxsargentdev]

You cant configure the benthos.yaml file manually when the chart is set to streams mode, this prevents enabling basic auth via:

http.basic_auth

http:
  address: 0.0.0.0:4195
  enabled: true
  root_path: /benthos
  debug_endpoints: false
  cert_file: ""
  key_file: ""
  cors:
    enabled: false
    allowed_origins: []
  basic_auth: # <----- cant set this, now I cant secure my streams
    enabled: false
    username: ""
    password_hash: ""
    algorithm: "sha256"
    salt: "

You really should be able to override this entire file when you are in streams mode as you would when not in streams mode....

I.e

    {{- tpl .Values.config . | nindent 4 }}