Defining blank rules on configuration files

[Bernardo-MG]

It should be posible to define blank rules in the configuration.

Something like this:

group:
  id: acknowledgement_transaction
  rules:
    - sequence:
      - record: acknowledgement
      - record: blank_20

Should become:

group:
  id: acknowledgement_transaction
  rules:
    - sequence:
      - record: acknowledgement
      - record: blank(20)

Where the number in parenthesis should be parsed, to indicate the size of the blank record.