Bug: widget does not contain CORS error handling

[fey]

Summary

If we create a workspace, integrate the widget and try to use it on another domain, we will get an error in devtools, and the widget itself will not display anything

Reproduction steps

1. create a workspace
2. add the widget to your site with a domain that is not in the workspace
3. call the snippet and press send, see devtools

Expected result

the widget handles errors and displays them in a form

Actual result

No response on the form

Browsers

Chrome

OS

Linux

[bazilval]

В целом, думаю эти ишьюс связаны #249

[kitdim]

Возьму

[Alena007S]

This error is still valid

• summary:
  When trying to log in to a account with an invalid password, no error appears
  environment:
  Google Chrome
  ОС Windows
  steps-to-reproduce:
  1. open the login page https://hexlet-correction.herokuapp.com/login?error
  2. Enter the correct Email
  3. Enter incorrect Password
  4. Press Login button
  expected-result:
  Login was not successful.
  The message "Bad credential" appears
  actual-result:
  Login was not successful.
  But the message error does not appear
  

[bazilval]

@Alena007S please make additional issue, cause this issue is about CORS error on widget

It will increase chances that someone fix that

[fey]

@kitdim can you take this task?