Global Ajax error handler

What does this MR do?

Introduces a new global Ajax error handler to show a flash warning about the error detail of XHR requests which failed with status code 404 and 500

Are there points in the code the reviewer needs to double check?

Double check the wording.

Why was this MR needed?

A global solution for the problem in the #17880 (closed)

What are the relevant issue numbers?

Fixes #17880 (closed)

Screenshots (if relevant)

For requests failed with 404 - 500

For requests failed with 401

mentioned in issue #17880 (closed)

Reassigned to @fatihacet

@fatihacet UX wise I think the text that looks like a link might not work. Maybe an i icon that is hoverable. The link looks clickable.

Also if we're using an icon, clicking it will copy the error to clipboard? In those popups it may be hard to copy error messages.

Added 1 commit:

• 84da0d9b - Added global ajax error handler to show a flash notification for failed requests.

Added 83 commits:

• 84da0d9b...5804b6a0 - 82 commits from branch master
• 0e8390bd - Added global ajax error handler to show a flash notification for failed requests.

Added 1 commit:

• 63f5c787 - Added global ajax error handler to show a flash notification for failed requests.

@jschatz1 I removed the more information link and the i icon as we discussed in Slack. Also I added a handler for 401 requests. See the screenshot in the MR description.

Reassigned to @jschatz1

Reassigned to @fatihacet

conflict

Added 126 commits:

• 63f5c787...2527ae6c - 125 commits from branch master
• 1898cb03 - Added global ajax error handler to show a flash notification for failed requests.

Milestone changed to %8.10

Reassigned to @jschatz1

@fatihacet What happens to all the other errors that already exist?

Reassigned to @fatihacet

If we do this we should make a separate MR to remove existing flash messages.

Reassigned to @dzaporozhets