Homogenize configuration management

[aeneasr]

To do:

• mutator.hydrator.api.retry.delayInMilliseconds => mutator.hydrator.config.api.retry.delay_in_milliseconds
• mutator.hydrator.api.retry.number => mutator.hydrator.api.retry.number_of_retries
• Replace json schema reference /fix-255/ with /master/
• Revert https://github.com/ory/oathkeeper/pull/258/files#diff-9f6f74101514723a98e882f06779ada8R53
• Revert https://github.com/ory/oathkeeper/pull/258/files#diff-4c51d95b26718af4a2ac3bec33e54e49L132-L135

mutators header and cookie now need to be configured in the main config like this:

  header:
    enabled: true
    config:
      headers:
        foo: bar

  # Configures the cookie mutator
  cookie:
    # Set enabled to true if the mutator should be enabled and false to disable the mutator. Defaults to false.
    enabled: true
    config:
      cookies:
        foo: bar

keto like this:

  # Configures the keto_engine_acp_ory authorizer
  keto_engine_acp_ory:
    # Set enabled to true if the authorizer should be enabled and false to disable the authorizer. Defaults to false.
    enabled: true

    config:
      # REQUIRED IF ENABLED - The base URL of ORY Keto, typically something like http(s)://<host>[:<port>]/
      base_url: http://my-keto/
      required_action: unknown
      required_resource: unknown

[aeneasr]

revert