Add some model to reduce complexity for most used source and sink

[giucris]

Describe the solution you'd like
In some cases it could be annoying to write the full format configuration for the most common source and sink.
It could be useful to have some facility

For example:

...
    - id: my_csv      
      source:           
        format: csv   
        options:       
          header: 'true'
          path: path/to/input/csv/

It could be done in the following way:

...
    - id: my_csv      
      source:           
        csv: path/to/input/csv/
        options:       
          header: 'true'