Easily build bodies and query strings

[visola]

In HTTPie you can easily pass in key-value pairs and have them be set correctly in your body or query strings. This is a really nice feature that saves a lot of time.

User Story

As a user, when executing a request, I want to be able to easily build a query string or body to add to my request.

Acceptance criteria

Basic functionality is to add this behavior to CLI arguments and also to profiles:

• Internally, request.Request now has a Values field
  • If method is GET and there are key-value pairs, URL encode and add them to the query string
  • If method is not GET
    • If content-type is not set or is JSON mime type, build a JSON object, ensure content-type and set the JSON in the body
    • If content-type is application/x-www-form-urlencoded, URL encode values and set them in the body
• from the CLI:
  • Accept dangling key-value pairs from the CLI and parse them correctly
• from the profiles:
  • requests now has a new attribute values that reads as a map of strings or array of string