Handle multiline paremeters in steps

[vlalanne]

Is your feature request related to a problem? Please describe.
When trying to compare complex object like JSON Http Response the single line step is not readable

Then the customer gets a HTTP response with status 400 and json payload: {"status": 400, "message": "Bad request: bad input: offer is not available for project"}

Describe the solution you'd like
By handling multi-line argument in step it becomes clearer

Then the customer gets a HTTP response with status 400 and json payload: 
    """
    {
        "status": 400,
        "message": "Bad request: bad input: offer is not available for project"
    }
    """"

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.