Warning the user when the audit page has a server error response in PSAT

[fellyph]

Feature Request

Description:
When the user audits a page with a server error, the PSAT extension returns the report with the cookies from the audit page, different from the CLI where the user can't see the audit page. PSAT the audit runs on the browser, but if the user downloads the report, the information about the status from the audit URL is lost.

This feature includes a warning on the cookies insight page to record that the audit page has an error that might affect the final audit result. On this scenario, when the page returns an error, the insights page should display a warning notifying this audit was affected by a server error:

If the server returns an error, steps like knowing breakages on the audit don't need to be processed.

Motivation:
Includes feedback on the Cookies insight report that the audit page returns a server error. It also includes the warning in the download report version.

User Story:
As a user, I want to receive a warning when the audit returns a server error so that I can save when the report is affected by an error.

Acceptance Criteria:

• When the user audit a page with a server error
• Cookies insight page return a warning
• The warning should be visible on the download report

Related : #801