Expand RabbitMQ validator to check loose credentials expressions.

[yongyan-gh]

Changes

• Update SEC101/041.RabbitMqCredentials validator to check for loose credentials. e.g.

  {
  "settings": [
  { "name": "RABBITMQ HOST", "value": "12.23.45.78" },
  { "name": "RABBITMQ PASSWORD", "value": "..." },
  { "name": "RABBITMQ PORT", "value": "5672" }, 
  { "name": "RABBITMQ USERNAME", "value": "guest" },
  ...
  ]
  }

  ...
  env:
  RABBITQ_HOST: ...
  RABBITMQ_USERNAME: ...
  RABBITMQ_PASSWORD: ...
  RABBITMQ_VHOST: ...

• Ignore the password in within common variable context e.g. $(...) {...} [...]
• Make the port number and virtual host name optional.
• Update official RabbitMQ.Client package to latest version.