Hide empty state on issues list when errors are present

What does this MR do and why?

Avoids showing empty state when errors prevent any items from loading in the issues list.

Previously if no issues successfully loaded it was possible that tab counts would show a number while simultaneously showing the empty state message, providing a confusing information clash. With this MR only the error alert will appear.

This does not...

• Change the nav counts (not intended to change)
• Clarify the error messaging or provide a way to retry (#463394)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

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Before	After	After (non-empty)

How to set up and validate locally

1. Pass an invalid value to force an error, such as http://gdk.test:3000/flightjs/Flight/-/issues/?sort=created_date&state=asdf&first_page_size=20 (state=asdf is the key)