[MD] UI Error messages/pop-ups/alerts for data source client errors

[zhongnansu]

Follow up of #2236 Apply appropriate UI error alerts for failed API call that uses datasource clients.

• [ ] index pattern page
• [ ] discover/visualization page
• [ ] ...

Update

for discover/visualization page, there's already logic to display error toast. We can leave it as it is, and refactor if further requested