Authorization tab

[danirod]

• Create a new tab page in the request notebook for the Authorization information.
• Design a class system similar to the one used for bodies, where different panels can co-exist and be chosen.
• Implement some authorization schemes:
  • Basic authorization as defined in RFC 7617
  • Digest authorization as defined in RFC 7616
  • Bearer authorization as defined in RFC 6750
• Make sure that if an authorization scheme is set, the Authorization header is automatically appended to HTTP requests.

I know what OAuth is an authorization scheme that would be highly requested, but the complexity at the moment makes it outside of the scope of this issue.