Analytics visualization designer: fail gracefully when error
What does this MR do and why?
Look for errors on the CubeJS responses, and display a user friendly error message when data fails to load.
Screenshots or screen recordings
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How to set up and validate locally
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Install the product analytics devkit and connect to your GDK by following the instructions here: https://gitlab.com/gitlab-org/analytics-section/product-analytics/devkit 
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Visit the visualisation designer: http://gdk.test:3000/gitlab-org/gitlab-shell/-/analytics/dashboards/visualization-designer 
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Disable your network within devtools in order to simulate an error, or block the endpoint, or modify the backend to throw 
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Click metric: Page Views -> All Pages 
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Request fails, error is now shown 
MR acceptance checklist
This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.
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I have evaluated the MR acceptance checklist for this MR. 
Related to #398407 (closed)