Fixes issue with semicolon in form data (CURL)

[someshkoli]

fixes #257
Curl requires form data to be enclosed in double quotes if form data value contains semicolon or comma

This PR adds check for the above conditions and adds the following changes

• adds check for semicolon and comma in form data
• encloses form data value if semicolon/comma is present
• Modifies sanitize function, adds follows
  • adds option to escape double quotes
  • adds option to escape back slash

[umeshp7]

https://travis-ci.com/github/postmanlabs/postman-code-generators/builds/169343297#L5074
Newman test for formdata is failing.
Please make sure the changes you have done are correct and works in all cases.

Look at the value of "qu", it should simply be "\"b\"". Why are there so many backslashes and double quotes added there?

Curl requires form data to be enclosed in double quotes if form data value contains semicolon or comma

Where are we checking if semicolon and/or comma are present in form data?

According to the image you shared, the , and ; have to be wrapped around double quotes if it occurs in a filename. Not for all kinds formdata values.

[someshkoli]

If we do that it conflicts with " inside the form data.
Also if we do that, form data values having "test" result in false respose, it takes string which is only present inside the quotes and does not consider quotes as a part of string. And if we try to escape those we get a whole new response from the backend. I have tried and tested the above approach and all the cases works with this

Also the "qu" = .... Works perfectly on local it's device , it's just failing in ci

[someshkoli]

Where are we checking if semicolon and/or comma are present in form data?

That approach failed for strings containing " so had to enclose all the form data in double quotes

@umeshp7 ^

[webholik]

Problem is that behavior of curl has changed in newer versions. Quoting for non-file data is not required in version 7.47.0 which is what CI runs and adding quotes breaks that build as then the output after running curl no longer matches the one in newmanResponses.json.