decodeURIComponent basic auth

[stevenvachon]

Describe the bug

• Got version: 11.1.3
• Node.js version: 12.16.3 and 14.2.0
• OS & version: macOS 10.15.4

Similar to #1234, basic auth values are not decoded before sending to http.request, resulting in authentication failure.

Code to reproduce

These send "%3Duser" and "%3Dpass" to http.request:

const url = new URL('http://host');
url.username = '=user';
url.password = '=pass';
got(new URL(url));

got({
  password: '=user',
  url: 'http://host',
  username: '=user'
});

const url = new URL('http://host');
got(`${url.protocol}//=user:=pass@${url.host}`);

Checklist

• I have read the documentation.
• I have tried my code with the latest version of Node.js and Got.

[szmarczak]

Duplicate of #1169