Support multiline variables in Options

[alturkovic]

Problem to solve

I am trying to use a JSON variable in the [Options] section. The only way to do this currently is to use a compacted version. It would be nice to be able to use a multiline variable for readability.

Proposal

Allow multiline variables similar how the body is defined.

Here is a concrete example of what I am trying to do:

GET http://localhost:8080/default
[Options]
variable: new-value=```json
{
  "key": "value
}
```
HTTP 200
[Captures]
default-value: body
[Asserts]
body != {{new-value}}

PUT http://localhost:8080/default
{{new-value}}
HTTP 200

I am trying to change the defaults of a certain endpoint only if they are different than the value I am trying to update them to. This type of a check would also probably need a better equality check (compare JSON equality, not string), but that is for another discussion.